Deutsch English
Otto-von-Guericke-Universität Magdeburg / FNW
ITP home AG home Forschung Publikationen Mitarbeiter Veranstaltungen Interessantes

Publikationen

2011:

  1. O. Götze, D. J. J. Farnell, R. F. Bishop, P. H. Y. Li, and J. Richter : "Heisenberg antiferromagnet on the kagome lattice with arbitrary spin: A higher-order coupled cluster treatment ", Phys. Rev. B. 84, 224428 (2011)
  2. M. Maksymenko, O. Derzhko, and J. Richter: "Localized states on triangular traps and low-temperature properties of the antiferromagnetic Heisenberg and repulsive Hubbard models ", Eur. Phys. J. B. 84, 307-408 (2011)
  3. O. V. Derzhko, T. E. Krokhmalskii, J. Richter: Quantum Heisenberg antiferromagnet on low-dimensional frustrated lattices, Theoretical and Mathematical Phys., 168(3): 1236-1245 (2011)
  4. J. Sirker, V. Y. Krivnov, D. V. Dmitriev, A. Herzog, O. Janson, S. Nishimoto, S.-L. Drechsler, and J. Richter: "J1-J2 Heisenberg model at and close to its z=4 quantum critical point", Phys. Rev. B 84, 144403 (2011)
  5. H.-J. Schmidt, A. Lohmann, and J. Richter: "Eighth-order high-temperature expansion for general Heisenberg Hamiltonians", Phys. Rev. B 84, 104443 (2011)
  6. M. Härtel, J. Richter, D. Ihle, J. Schnack, and S.-L. Drechsler: "Thermodynamics of the one-dimensional frustrated Heisenberg ferromagnet with arbitrary spin", Phys. Rev. B 84, 104411 (2011)
  7. D. J. J. Farnell, R. Darradi, R. Schmidt, and J. Richter: "Spin-half Heisenberg antiferromagnet on two archimedian lattices: From the bounce lattice to the maple-leaf lattice and beyond", Phys. Rev. B 84, 104406 (2011)
  8. S. Nishimoto, S.-L. Drechsler, R. O. Kuzian, J. van den Brink, J. Richter, W. E. A. Lorenz, Y. Skourski, R. Klingeler, and B. Büchner: "Saturation Field of Frustrated Chain Cuprates: Broad Regions of Predominant Interchain Coupling", Phys. Rev. Lett. 107, 097201 (2011)
  9. D. J. J. Farnell, R. F. Bishop, P. H. Y. Li, J. Richter, and C. E. Campbell: "Frustrated Heisenberg antiferromagnet on the honeycomb lattice: A candidate for deconfined quantum criticality", Phys. Rev. B 84, 012403 (2011)
  10. M. Härtel, J. Richter, and D. Ihle: "Thermodynamics of the frustrated one-dimensional spin-1/2 Heisenberg ferromagnet in a magnetic field ", Phys. Rev. B 83, 214412 (2011)
  11. M. Maksymenko, O. Derzhko and J. Richter : "Low-Temperature Properties of the Quantum Heisenberg Antiferromagnet on Some One-Dimensional Lattices Containing Equilateral Triangles ", Acta Physica Polonica A 119, 860 (2011)
  12. S.-L. Drechsler, S. Nishimoto, R. O. Kuzian, J. Málek, W. E. A. Lorenz, J. Richter, J. van den Brink, M. Schmitt, and H. Rosner: "Comment on "Two-Spinon and Four-Spinon Continuum in a Frustrated Ferromagnetic Spin-1/2 Chain"", Phys. Rev. Lett. 106, 219701 (2011)
  13. H. Jeschke, I. Opahle, H. Kandpal, R. Valenti, H. Das, T. Saha-Dasgupta, O. Janson, H. Rosner, A. Brühl, B. Wolf, M. Lang, J. Richter, S. Hu, X. Wang, R. Peters, T. Pruschke, and A. Honecker: "Multistep Approach to Microscopic Models for Frustrated Quantum Magnets: The Case of the Natural Mineral Azurite", Phys. Rev. Lett. 106, 217201 (2011)
  14. V. Derzhko, O. Derzhko, and J. Richter: "Exact solution of a spin-1/2 XX chain with three-site interactions in a random transverse field: Influence of randomness on the quantum phase transition", Phys. Rev. B 83, 174428 (2011)
  15. T. Verkholyak, J. Strecka, M. Jascur, and J. Richter: "Magnetic properties of the quantum spin-1/2 XX diamond chain: The Jordan-Wigner approach", Euro. Phys. J. B 80, 433 (2011)
  16. A. Honecker, S. Hu, R. Peters, and J. Richter: "Dynamic and thermodynamic properties of the generalized diamond chain model for azurite ", J. Phys.: Condens. Matter 23, 164211 (2011)
  17. A. A. Tsirlin, R. Zinke, J. Richter, and H. Rosner: "Spiral ground state in the quasi-two-dimensional spin-1/2 system Cu2GeO4", Phys. Rev. B 83, 104415 (2011)
  18. J. Reuther, P. Wölfle, R. Darradi, W. Brenig, M. Arlego, J. Richter: "Quantum phases of the planar antiferromagnetic J1-J2-J3 Heisenberg model", Phys. Rev. B 83, 064416 (2011)

2010:

  1. T. Verkholyak, J. Strecka, M. Jascur, J. Richter: "Spin-1/2 XXZ Diamond Chain within the Jordan-Wigner Fermionization Approach", Acta Physica Polonica A 118 , 978 (2010)
  2. O. Derzhko, M. Maksymenko, J. Richter, A. Honecker, R. Moessner: "Magnetic Properties of the Hubbard Model on Kagome Stripes", Acta Physica Polonica A 118 , 736 (2010)
  3. O. Derzhko, T. Krokhmalskii, J. Richter: "Emergent Ising degrees of freedom in frustrated two-leg ladder and bilayer s=1/2 Heisenberg antiferromagnets", Phys. Rev. B 82, 214412 (2010)
  4. R. Zinke, J. Richter and S.-L. Drechsler: "Spiral correlations in frustrated one-dimensional spin-1/2 Heisenberg J1-J2-J3 ferromagnets", J. Phys.: Condens. Matter 22, 446002 (2010)
  5. O. Janson, J. Richter, P. Sindzingre, and H. Rosner: " Coupled frustrated quantum spin-1/2 chains with orbital order in volborthite Cu3V2O7(OH)22H2O", Phys. Rev. B 82, 104434 (2010)
  6. H.-J. Schmidt and J. Richter: " Exact ground states for coupled spin trimers", J. Phys. A: Math. Theor. 43, 405205 (2010)
  7. N. B. Ivanov, J. Schnack, R. Schnalle, J. Richter, P. Kögerler, G. N. Newton, L. Cronin, Y. Oshima, and H. Nojiri: "Heat Capacity Reveals the Physics of a Frustrated Spin Tube", Phys. Rev. Lett. 105, 037206 (2010)
  8. J. Richter, R. Darradi, J. Schulenburg, D. J. J. Farnell, and H. Rosner "Frustrated spin-1/2 J1-J2 Heisenberg ferromagnet on the square lattice studied via exact diagonalization and coupled-cluster method", Phys. Rev. B 81, 174429 (2010)
  9. M. Härtel, J. Richter, D. Ihle and S.-L. Drechsler "Thermodynamics of a two-dimensional frustrated spin-1/2 Heisenberg ferromagnet", Phys. Rev. B 81, 174421 (2010)
  10. W. A. Nunes, J. Ricardo de Sousa, J. Roberto Viana and J. Richter "The quantum spin-1/2 J1–J2 antiferromagnet on a stacked square lattice: a study of effective-field theory in a finite cluster", J. Phys.:Condens. Matter 22, 146004 (2010)
  11. V. Ravi Chandra1, N. B. Ivanov and J. Richter "Frustrated spin ladder with alternating spin-1 and spin-1/2 rungs", Phys. Rev. B 81, 024409 (2010)
  12. O. Derzhko, J. Richter, A. Honecker, M. Maksymenko, and R. Moessner "Low-temperature properties of the Hubbard model on highly frustrated one-dimensional lattices", Phys. Rev. B 81, 014421 (2010)
  13. J. Richter, J. Schulenburg "The spin-1/2 J1–J2 Heisenberg antiferromagnet on the square lattice: Exact diagonalization for N = 40 spins", Eur. Phys. J. B 73, (2010) 117-124

2009:

  1. S.-L. Drechsler, J. Málek, S. Nishimoto, J. Richter, R. Kuzian, H. Rosner and H. Eschrig "Low-temperature pecularities of the optical response in undoped cuprates", Journal of Physics: Conference Series 150, 042026 (2009)
  2. N. B. Ivanov, J. Richter, J. Schulenburg "Phase diagram of diamond chains with four-spin exchange interaction", Journal of Optoelectronics and Advanced Materials, Vol. 1, No. 3 (2009) 502-504
  3. A. Honecker, O. Derzhko, J. Richter "Ground-state degeneracy and low-temperature thermodynamics of correlated electrons on highly frustrated lattices", Physica B, 404 (2009) 3316-3319
  4. J. Richter, J. Schulenburg, P. Tomczak, D. Schmalfuß "The Heisenberg antiferromagnet on the square-kagomé lattice", Condensed Matter Physics, 2009, Vol. 12, No. 3, p. 507
  5. D. J. J. Farnell, R. Zinke, J. Schulenburg and J. Richter "High-order coupled cluster method study of frustrated and unfrustrated quantum magnets in external magnetic fields", J. Phys.: Condens. Matter 21 (2009) 406002 (12pp)
  6. I. J. Junger, D. Ihle and J. Richter "Thermodynamics of layered Heisenberg magnets with arbitrary spin", Phys. Rev. B 80, 064425 (2009)
  7. D. J. J. Farnell, J. Richter, R. Zinke and R. F. Bishop "High-Order Coupled Cluster Method (CCM) Calculations for Quantum Magnets with Valence-Bond Ground States ", Journal of Statistical Physics 135, 175-198
  8. R. Zinke, S.-L. Drechsler, and J. Richter "Influence of interchain coupling on spiral ground-state correlations in frustrated spin-1/2 J1-J2 Heisenberg chains", Phys. Rev. B 79, 094425 (2009)
  9. N. B. Ivanov, J. Richter, J. Schulenburg "Diamond chains with multiple-spin exchange interactions", Phys. Rev. B 79, 104412 (2009)
  10. H. Rosner, M. Schmitt, D. Kasinathan, A. Ormeci, J. Richter, S.-L. Drechsler, and M. D. Johannes "Comment on "Electronic structure of spin-1/2 Heisenberg antiferromagnetic systems: Ba2Cu(PO4)2 and Sr2Cu(PO4)2"", Phys. Rev. B 79, 127101 (2009)
  11. O. Janson, R. Richter and H. Rosner "Intrinsic peculiarities of real material realizations of a spin-1/2 kagomé lattics", Journal of Physics: Conference Series 145, 012008 (2009)
  12. O. Derzhko, R. Richter and A. Honecker "Low-temperature thermodynamics of one class of flat-band models", Journal of Physics: Conference Series 145, 012059 (2009)
  13. J. Richter, M. Härtel, D. Ihle and S.-L. Drechsler "Thermodynamics of the frustrated ferromagnetic spin-1/2 Heisenberg chain", Journal of Physics: Conference Series 145, 012064 (2009)
  14. R. Darradi, J. Richter, J. Schulenburg, R. F. Bishop and P. H. Y. Li "The ground-state magnetic ordering of the spin-1/2 frustrated J1-J2 XXZ model on the square lattice", Journal of Physics: Conference Series 145, 012049 (2009)
  15. O. Derzhko, A. Honecker and J. Richter "Exact low-temperature properties of a class of highly frustrated Hubbard models", Phys. Rev. B 79, 054403 (2009)

2008:

  1. R. Daradi, O. Derzhko, R. Zinke, J. Schulenburg, S.E. Krüger and J. Richter "Ground state phases of the spin-1/2 J1-J2 Heisenberg antiferromagnet on the square lattice: a high-order coupled cluster treatment", Phys. Rev. B 78 , 214415-1-10 (2008)
  2. J. Richter, O. Derzhko and A. Honecker "The Sawtooth Chain: From Heisenberg Spins to Hubbard Electrons", Int. Journ. of Mod. Phys. B 22 , 4418 (2008)
  3. M. Härtel, J. Richter, D. Ihle and S.-L. Drechsler "Thermodynamics of a one-dimensional frustrated spin-1/2 Heisenberg ferromagnet", Phys. Rev. B 78 , 174412-1 (2008)
  4. R. F. Bishop, P. H. Y. Li, R. Darradi, J. Richter and C. E. Campbell "The Effect of anisotropy on the ground-state magnetic ordering of the spin-1 quantum J1XXZ-J2XXZ model on the square lattice", J. Phys. Condens. Matter 20 , 415213 (2008)
  5. O. Janson J. Richter and H. Rosner "Modifies Kagome Physics in the Natural Spin-1/2 Kagome Lattice System: Kapellastite Cu3Zn(OH)6Cl2 and Haydeeite Cu3Mg(OH)6Cl2", Phys. Rev. Lett. 101, 106403 (2008)
  6. J. Richter and O. Derzhko "Correlated systems on geometrically frustrated lattices: From magnons to electrons", Condensed Matter Physics in the Prime of 21st Century, ed by J. Jedrzejewski, Proceeding of the 43rd Karpacz Winter School on Theoretical Physics, World Scientific, Singapore, 237-270 (2008)
  7. R. F. Bishop, P. H. Y. Li, R. Darradi, J. Schulenburg and J. Richter "Effect of anisotropy on the ground-state magnetic ordering of the spin-half quantum J1XXZ-J2XXZ model on the square lattice", Phys. Rev. B 78 , 054412 (2008)
  8. A. M. Ghorayeb, M. Costes, M. Goiran, J.-M. Broto, S. Schäfer, R. Hayn, J. Richter, P. Millet and A. Stepanov "High-field magnetization and electron spin resonance in the spin gap system η-Na1.286V2O5", Phys. Rev. B 77 , 224434 (2008)
  9. R. F. Bishop, P. H. Y. Li, R. Darradi and J. Richter "The quantum J1-J'1-J2 spin-1/2 Heisenberg model: influence of the interchain coupling on the ground-state magnetic ordering in two dimensions", J. Phys. Condens. Matter 20 , 255251 (2008)
  10. R. F. Bishop, P. H. Y. Li, R. Darradi and J. Richter "The quantum J1-J'1-J2 spin-1 Heisenberg model: Influence of the interchain coupling on the ground-state magnetic ordering in 2D", Europhys. Lett. 83 , 47004 (2008)
  11. R. Zinke, J. Schulenburg and J. Richter "Ground-state long-range order in quasi-one-dimensional Heisenberg quantum antiferromagnets: High-order coupled-cluster calculations", Eur. Phys. J. B 61 , 147-152 (2008)
  12. O. Derzhko, J. Richter and T. Krokhmalskii "Quantum Heisenberg Antiferromagnet in Frustrated Bilayer Lattice in Strong Magnetic Fields", Acta Physica Polonica A 113 , 433-463 (2008)

2007:

  1. O. Derzhko, A. Honecker and J. Richter "Low-temperature thermodynamics for a flat-band ferromagnet: Rigorous versus numerical results", Phys. Rev. B 76 , 220402(R) (2007)
  2. O. Derzhko, J. Richter, A. Honecker and H.-J. Schmidt "Universal properties of highly frustrated quantum magnets in strong magnetic fields", Low Temperatur Physics 33 No. 9, 745-756 (2007)
  3. S.-L. Drechsler, N. Tristan, B. Büchner, J. Richter, J. Málek, O. Volkova, A. Vasiliev, M. Schmitt, A. Ormeci, C. Loison, W. Schnelle, A.S. Moskvin, A.A. Grippius, A. Prokofiev, H. Rakoto, J.-M. Broto and H. Rosner "Helimagnetism and weak ferromagnetism in edge-shared chain cuprates", Journ. of Magnetism and Magnetic Materials 316", 306-312 (2007)
  4. A. Honecker and J. Richter "Enhanced low-temperature entropy and flat-band ferromagnetism in the t-J model on the sawtooth lattice", Journal of Magnetism and Magnetic Materials 310, 1331 (2007)
  5. S.-L. Drechsler, N. Tristan, R. Klingeler, B. Büchner, J. Richter, J. Málek, O. Volkova, A. Vasiliev, M. Schmitt, A. Ormeci, C. Loison, W. Schnelle and H. Rosner "Helimagnetism and weak ferromagnetism in NaCU2O2 and related frustrated chain cuprates" J. Phys.: Condens. Matter 19", 145230 (2007)
  6. R. W. Chhajlany, P. Tomczak, A. Wójcik and J. Richter "Entanglement in the Majumdar-Ghosh model", Phys. Rev. A 75, 032340 (2007)
  7. S.-L. Drechsler, O. Volkova, A.N. Vasiliev, N. Tristan, J. Richter, M. Schmitt, H. Rosner, J. Málek, R. Klingeler, A. A. Zvyagin and H. Büchner "Frustrated Cuprate Route from Antiferromagnetic to Ferromagnetic Spin-1/2 Heisenberg Chains: Li2ZrCuO4 as a Missing Link near the Quantum Critical Point", Phys. Rev. Lett. 98, 077202 (2007)
  8. D. V. Dmitriev, V. Ya. Krivnov and J. Richter "Zigzag spin-S chain near the ferromagnet-antiferromagnet transition point", Phys. Rev. B 75, 014424 (2007)
  9. O. Derzhko, J. Richter, A. Honecker and H.-J. Schmidt "Universal properties of highly frustrated quantum magnets in strong magnetic fields", Fizika Nizkikh Temperatur 33 No. 9, 982-996 (2007)
  10. J. Schnack, R. Schmidt and J. Richter "Enhanced magnetocaloric effect in frustrated magnetic molecules with icosahedral symmetry", Phys. Rev. B 76, 054413 (2007)
  11. J. Richter, R. Darradi, R. Zinke and R. F. Bishop "Frustrated quantum antiferromagnets: application of high-order coupled cluster method", International Jounal of Modern Physics B 21, 2273-2288 (2007)

2006:

  1. M. D. Johannes, J. Richter, S.-L. Drechsler and H. Rosner "Sr2Cu(PO4)2: A real material realization of the one-dimensional nearest neighbor Heisenberg chain ", Phys. Rev. B. 74, 174435 (2006)
  2. J. Schnack, H.-J. Schmidt, A. Honecker, J. Schulenburg and J. Richter " Exact eigenstates of highly frustrated spin lattices probed in high fields", J. Phys.: Conf. Ser. 51, 43-46 (2006)
  3. J. Richter, O. Derzhko and T. Krokhmalskii " Finite-temperatur order-disorder phase transition in a frustrated bilayer quantum Heisenberg antiferromagnet in strong magnetic fields", Phys. Rev. B 74, 144430 (2006)
  4. D. Schmalfuß, R. Darradi, J. Richter, J. Schulenburg and D. Ihle " Quantum J_1-J_2 Antiferromagnet oa a Stacked Square Lattice: Influence of the Interlayer Coupling on the Ground-State Magnetic Ordering", Phys. Rev. Lett. 97, 157201 (2006)
  5. P. Tomczak, A. Molinska, J. Richter, J. Schulenburg " The ground-state of the quantum spin-1/2 Heisenberg antiferromagnet on square kagome lattice: resonating valence bond description ", Acta Phys. Polonica A 109 /81-787 (2006)
  6. H.-J. Schmidt, J. Richter, R. Moessner " Linear independence of localized magnon states", J. Phys. A: Math. Gen. 39 10673-10690 (2006)
  7. O. Derzhko, J. Richter " Universal low-temperature behavior of frustrated quantum antiferromagnets in the vicinity of the saturation field", Eur Phys. J. B 52 23-36 (2006)
  8. N.B. Ivanov, J. Richter "Magnetic phase diagramm of a frustrated ferrimagnetic ladder: Relation to the one-dimensional boson Hubbard model", Phys. Rev. B 73 132407-1-4 (2006)
  9. S.-L. Drechsler, J. Richter, A.A. Gippius, A. Vasiliev, A.A. Bush, A.S. Moskvin, J. Malek, YU. Prots, W. Schnelle and H. Rosner "Helical ground state and weak ferromagnetism in the edge-shared chain cuprate NaCu2O2", Europhysics Letters 73 (1) 83-89 (2006)
  10. S.E. Krüger, R. Darradi, J. Richter and D.J.J. Farnell "Direct calculation of the spin stiffness of the spin-1/2 Heisenberg antiferromagnet on square, triangular and cubic lattices using the coupled cluster method", Phys. Rev. B 73 094404 (2006)

2005:

  1. A. Honecker and J. Richter "Entropy of fermionic models on highly frustrated lattices", Condensed Matter Physics 8 No. 4(44),813-824 (2005)
  2. D. Schmalfuß, J. Richter and D. Ihle "Green's function theory of quasi-two-dimensional spin-half Heisenberg ferromagnets: stacked square versus stacked kagomé lattice", , Phys. Rev. B 72 224405 (2005)
  3. D. J. J. Farnell, J. Schulenburg, J. Richter and K. A. Gernoth "High-order coupled cluster calculations via parallel processing: An illustration for CaV4O9", Phys. Rev. B 72 172408 (2005)
  4. O. Derzhko, J. Richter and J. Schulenburg "Structural distortion of frustrated quantum spin lattices in high magnetic fields", Phys. Stat. Sol. (B) 242, No.15, 3189-3194 (2005)
  5. O. Derzhko and J. Richter "Structural instability of two- and three-dimensional pyrochlore spin lattices in high magnetic fields", Phys. Rev. B 72 094437 (2005)
  6. A. Honecker, D.C. Cabra, M.D. Grynberg, P.C.W. Holdsworth, P. Pujol, J. Richter, D. Schmalfuß and J. Schulenburg "Ground state and low-lying excitations of the spin-1/2 XXZ model on the kagomé lattice at magnetizations 1/3", Physica B 359-361 1391-1393 (2005)
  7. I. Juhász Junger, D. Ihle and J. Richter "Thermodynamics of S>=1 ferromagnetic Heisenberg chains with uniaxial single-ion anisotropy" , Phys. Rev. B 72 064454 (2005)
  8. R. Darradi, J. Richter and D.J.J. Farnell "Coupled cluster treatment of the Shastry-Sutherland antiferromagnet", Phys. Rev. B 72 104425 (2005)
  9. J. Richter "Localized-magnon states in strongly frustrated quantum spin lattices", Fizika Nizkikh Temperatur 31 Number 8-9, 918-928 (2005)
  10. R. Schmidt, J. Richter and J. Schnack "Frustration effects in magnetic molecules", Journ. of Magnetism and Magnetic Materials 295, 164-167 (2005)
  11. M. Enderle, C. Mukherjee, B. F�k, R. K. Kremer, J.-M. Broto, H. Rosner, S.-L. Drechsler, J. Richter, J. Má lek, A. Prokofiev, W. Assmus, S. Pujol, J.-L. Raggazzoni, H. Rakoto, M. Rheinstädter and H. M. Rønnow "Quantum helimagnetism of the frustrated spin-1/2 chain LiCuVO4", Europhysics Letters 70 (2), 237-243 (2005)
  12. D. C. Cabra, M. D. Grynberg, P. C. W. Holdsworth, A. Honecker, P. Pujol, J. Richter, D. Schmalfuß, J. Schulenburg "Quantum kagome antiferromagnet in a magnetic field: Low-lying non-magnetic excitations versus valence-bond crystal order", Phys. Rev. B. 71, 144420 (2005)
  13. S.-L. Drechsler, J. Richter, J. Málek, A.S. Moskvind, R. Klingelera and H. Rosner "Spiral vs. ferromagnetic in-chain order in edge-shared cuprates", Journ. of Magnetism and Magnetic Materials 290-291, 345-348 (2005)
  14. S.-L. Drechsler, J. Málek, J. Richter, A. S. Moskvin, A. A. Gippius and H. Rosner "Comment on "Competition between Helimagnetism and Commensurate Quantum Spin Correlations in LiCu2O2", Phys. Rev. Lett. 94, 039705 (2005)
  15. R. Darradi,J. Richter and J.J. Farnell "Influence of the spin quantum number S on the zero-temperature phase transition in the square-lattice J-J' model" , J. Phys.: Condens. Matter 17, 341-350 (2005)

2004:

  1. D. Schmalfuß, J. Richter and D. Ihle "Absence of long-range order in a spin-half Heisenberg antiferromagnet ont the stacked kagomé lattice" , Phys. Rev. B. 70, 184412 (2004)
  2. J. Richter, J. Schulenburg, A. Honecker and D. Schmalfuß "Absence of magnetic order for the spin-half Heisenberg antiferromagnet on the star lattice" , Phys. Rev. B. 70, 174454 (2004)
  3. O. Derzhko and J. Richter "Finite low-temperature entropy of some strongly frustrated quantum spin lattices in the vicinity of the saturation field" , Phys. Rev. B. 70, 104415 (2004)
  4. J. Junger, D. Ihle, J. Richter and A. Kümper "Green-function theory of the Heisenberg ferromagnet in a magnetic field" , Phys. Rev. B. 70, 104419 (2004)
  5. J. Richter, O. Derzhko and J. Schulenburg "Magnetic-Field Induced Spin-Peierls Instability in Strongly Frustrated Quantum Spin Lattices" , Phys. Rev. Lett. 93, 107206 (2004)
  6. R. Darradi, J. Richter and S.E. Krüger "The influence of Ising anisotropy on the zero-temperature phase transition in the square lattice spin-1/2 J-J' model" , J. Phys. Condens. Matter 16, 2681-2687 (2004)
  7. A. Honecker, J. Schulenburg and J. Richter "Magnetism plateaus in frustrated antiferromagnetic quantum spin models" , J. Phys. Cond. Matter 16, 749-758 (2004)
  8. U. Schollwöck, J. Richter D. J. J. Farnell R. F. Bishop, Eds. "Quantum magnetism" , Lecture Notes in Phys. 645
  9. J. Richter, J. Schulenburg, A. Honecker "Quantum magnetism in two dimensions: From semi-classical N'eel order to magnetic disorder" Quantum magnetism Lecture Notes in Phys. 645 p. 85
  10. J. Richter, J. Schulenburg, A. Honecker J. Schnack and H.-J. Schmidt "Exact eigenstates and macroscopic magnetization jumps in strongly frustrated spin lattices" , J. Phys. Cond. Matter 16, 779-784 (2004)
  11. A. Voigt, W. Wenzel, J. Richter and P. Tomczak "The anisotropic quantum antiferromagnet on the Sierpinski gasket: Ground state thermodynamiks" , Eur. Phys. J. B. 38, 49-58 (2004)
  12. V. Ravi Chandra, Diptimen Sen, N. B. Ivanov and J. Richter "Antiferromagnetic sawtooth chain with spin-1/2 and spin-1 sites" , Phys. Rev. B 69, 214406 (2004)
  13. O. Derzhko, J. Richter, T. Krokhmaskii and O. Zaburannyi "Regularly altering spin 1/2 anisotropic XY chains: The ground-state and thermodynamic properties" , Phys. Rev. E 69, 066112 (2004)
  14. N. B. Ivanov and J. Richter "Phase diagram of a frustrated mixed-spin ladder with diagonal bonds" , Phys. Rev. B 69, 214420 (2004)

2003:

  1. R.O. Kuzian, R. Hayn, and J. Richter "Recursion method and one-hole spectral function of the Majumdar-Ghosh model" , Eur. Phys. J. B 35, 21-31 (2003)
  2. O. Derzhko, T. Verkholyak, R. Schmidt, and J. Richter "Square lattice s=1/2 XY model and the Jordan-Wigner fermions: the ground-state and thermodynamic properties" , Physica A 320, 407 (2003)
  3. O. Derzhko, J. Richter, T. Krokhaalskii, and O. Zabruannyi "Quantum phase transition in a transverse ising chain with regularly varying parameters", Acta Phys. Polonica B 34, 1387 (2003)
  4. D. Schmalfuß, R. Herms, J. Richter, and J. Schulenburg "Ground-state phases in a system of two competing square-lattice Heisenberg antiferromagnets" , J. Phys. Cond. Matter 15, 2667 (2003)
  5. P. Tomczak, and J. Richter "Specific heat of the spin-1/2 Heisenberg antiferromagnet on squagome lattice", Journ. Phys. A: Math. Gen. 36, 5399 (2003)

2002:

  1. R. Schmidt, J. Schulenburg, J. Richter, and D. D. Betts "Spin-1/2 J1-J2 model on the body-centered cubic lattice" , Phys. Rev. B. 66, 224406 (2002)
  2. S. Krüger, D. J. J. Farnell, and J. Richter "Coupled cluster treatments of Quantum magnets: Two examples," Proceedings of the 11th Intern. Conf. Recent Progress in Many-Body Theories ed. by R. F. Bishop, T. Brandes, K. A. Gernoth, Y. Xian World Scientific New Jersey, London, Singapore, Hong Kong, 365-382, (2002)
  3. A. Voigt and J. Richter "Quantum disorder of an antiferromagnetic spin model on the Sierpinski gasket" , Proceedings of the 11th Intern. Conf. Recent Progress in Many-Body Theories ed. by R. F. Bishop, T. Brandes, K. A. Gernoth, Y. Xian World Scientific New Jersey, London, Singapore, Hong Kong, 111-114, (2002)
  4. O. Derzhko, J. Richter, and T. Verkholyak "2D quantum spin models and Jordan-Wigner fermions" , Czechoslovak Journal of Phys. 52, Suppl. A, A41-A44 (2002)
  5. O. Derzhko, J. Richter, and O. Zaburannyi "Magnetization processes in quantum spin chains with regularly varying exchange interactions and field" , Journ. of Magn. and Magnet. Mat. 242-245, 1044 (2002)
  6. N. B. Ivanov, J. Richter, and D. J. J. Farnell "Magnetic phases of the mixed-spin J1-J2-Heisenberg model on a square lattice" , Phys. Rev. B. 66, 014421 (2002)
  7. O. Derzhko, J. Richter, T. Krokhmalkskiil, and O. Zaburannyi "Quantum phase transitions in alternating transverse Ising chains: Analytical and numerical results" , Phys. Rev. B. 66, 144401 (2002)
  8. J. Schulenburg and J. Richter "Sequence of first-order quantum phase transitions in a frustrated spin half dimer-plaquette chain" , Phys. Rev. B. 66, 134419 (2002)
  9. D. Schmalfuß, P. Tomczak, J. Schulenburg, and J. Richter "The spin-1/2 Heisenberg antiferromagnet on a 1/7-depleted triangular lattice: Ground-state properties" , Phys. Rev. B. 65, 224405 (2002)
  10. J. Schulenburg, A. Honecker, J. Schnack, J. Richter, and H.-J. Schmidt "Macroscopic Magnetization Jumps due to Independent Magnons in Frustrated Quantum Spin Lattices" , Phys. Rev. Lett. 88, 167207 (2002)
  11. J. Schulenburg, and J. Richter "Infinite series of magnetization plateaus in the frustrated dimer-plaquette chain" , Phys. Rev. B 65, 054420 (2002)

2001:

  1. J. Schnack, H.J. Schmidt, J. Richter, and J. Schulenburg "Independent magnon states on magnetic polytopes" , Eur. Phys. J. B 24, 475 (2001)
  2. A. Voigt J. Richter, and P. Tomczak "The quantum Heisenberg antiferromagnet on the Sierpinski gasket: an exact diagonalization study" , Physica A 299, 461 (2001)
  3. S.E. Krüger and J. Richter "Influence of quantum fluctuations on zero-temperature phase transitions between collinear and noncollinear states in frustrated spin systems" , Phys. Rev. B 64, 0244331 (2001)
  4. P. Thomczak, J. Schulenburg, J. Richter, and A.R. Ferchmin "The ground state of the spin-½ Heisenberg antiferromagnet on an Archimedean 4-6-12 lattice" , Journ. Phys.: Cond. Matter 13, 3851 (2001)
  5. J. Richter, S.E. Krüger, D.J.J. Farnell, and R.F. Bishop "Quantum phase transitions in spin systems" , World Scientific: Series on Advances in Quantum Many-Body Theory 5, 239 (2001)
  6. O. Derzhko, J. Richter, and T. Verkholyak "Jordan-Wigner fermions and the spin-½ anisotropic XY model on a square lattice" , Acta Physica Polonica B 32, 3427 (2001)
  7. P. Tomczak and J. Richter, "Quantum phase transitions in the J-J ' Heisenberg and XY spin-½ antiferromagnets on a square lattice: finite-size scaling analysis", J. Phys. A: Math. Gen. 34, 461 (2001)
  8. J. Schulenburg, J.S. Flynn, D. D. Betts, and J. Richter, "Exact diagonalization of the S=1/2 XY ferromagnet on finite bcc lattices to estimate T=0 properties on the infinite lattice" , Eur. Phys. J. B 21, 191 (2001)
  9. N.B. Ivanov and J. Richter, "Collective excitations in ferrimagnetic Heisenberg ladders" , Phys. Rev. B 63, 144429 (2001)

2000:

  1. R.F. Bishop, D.J.J. Farnell, S.E. Krüger, J.B. Parkinson, J. Richter, and C. Zeng, "High-order coupled cluster method calculations for the ground- and excited-state properties of the spin-half XXZ model" , Journ. Phys.: Condens. Matter 12, 6887 (2000)
  2. O. Derzhko, J. Richter, and Oles Zaburannyi, "Local magnetic properties of periodic nonuniform spin-1/2 XX chains" , J. Magn. Magn. Mat. 222, 207 (2000)
  3. J. Richter, U. Schollwöck, and N.B. Ivanov, "Quantum phase transition in frustrated ferro- and ferrimagnets", Physica B 281-282, 845 (2000)
  4. O. Derzhko, J. Richter, and O. Zaburannyi, "Thermodynamic properties of the periodic nonuniform spin-1/2 isotropic XY chain in a transverse field" , Physica A 282, 495 (2000)
  5. D. Schmalfuß, S.E. Krüger, and J. Richter, "Lieb-Mattis model for two interpenetrating antiferromagnets", Acta Physica Polonica A 97, 377 (2000)
  6. S.E. Krüger, D. Schmalfuß, and J. Richter, "Diagonalization of a bosonic quadratic form using CCM: Application on a system with two interpenetrating square lattice antiferromagnets" , Acta Physica Polonica A 97, 951 (2000)
  7. A. Voigt and J. Richter, "Marshall-Peierls sign rule in frustrated Heisenberg chains" , Acta Physica Polonica A 97, 979 (2000)
  8. J. Schulenburg, J. Richter, and D. D. Betts, "Heisenberg antiferromagnet on a 1/7-depleted triangular lattice", Acta Physica Polonica A 97, 971 (2000)
  9. S.E. Krüger, J. Richter, J. Schulenburg, D.J.J. Farnell, and R.F. Bishop, "Quantum phase transitions of a square-lattice Heisenberg antiferromagnet with two kinds of nearest-neighbour bonds: A high-order coupled-cluster treatment" , Phys. Rev. B 61, 14607 (2000)
  10. O. Derzhko, J. Richter, and O. Zaburannyi, "Spin-Peierls instability in a quantum spin chain with Dzyahinskii-Moriya interaction" , Journ. Phys.: Condens. Matter 12 8661 (2000)
  11. O. Derzhko, J. Richter, and O. Zaburannyi, "Spin-1/2 periodic nonuniform XX chains and the spin-Peierls instability" , Acta Physica Polonica A 97/5 931 (2000)

1999:

  1. O. Derzhko and J. Richter, "Thermodynamic properties of a spin-1/2 transverse XY chain with Dzyaloshinski-Moriya interaction: Exact solution for correlated Lorentzian disorder" , Phys. Rev. B 59, 100 (1999)
  2. P. Tomczak and J. Richter, "Ground state of the spin-1/2 Heisenberg antiferromagnet on a two-dimensional square-hexagonal-dodecagonal lattice" , Phys. Rev. B 59, 107 (1999)
  3. J. Richter, D. Schmalfuß, and S.E. Krüger, "Magnetic ordering in a system with two interpenetrating square lattice antiferromagnets" Physica B 259-261, 911 (1999)
  4. A. Voigt, "Grundzustand und Thermodynamik frustrierter Quantenspinsysteme" Universität Magdeburg, Fakultät für Naturwissenschaften, Dissertation A, verteidigt am 29.06.1999, 111 Seiten
  5. O. Derzhko, J. Richter, and V. Derzhko, "Thermodynamics of the s=1/2 transverse XX chain with Dzyaloshinskii-Moriya interaction in the presence of correlated Lorentzian disorder" , Ann. Phys. 8, 49 (1999)
  6. O. Derzhko, J. Richter, and O. Zaburannyi, "The spin 1/2-transverse XX chain with regularly alternating bonds and fields" , Phys. Lett. A 262, 217 (1999)

1998:

  1. J. Richter, A. Voigt, J. Schulenburg, N.B. Ivanov, and R. Hayn, "Magnetic model for Ba2Cu3O4Cl2", J. Magn. Magn. Mat. 177-181, 737 (1998)
  2. J. Richter, N.B. Ivanov, and J. Schulenburg, "The antiferromagnetic spin 1/2 chain with competing dimers and plaquettes -- Numerical versus exact results" , J. Phys.: Condens. Matter 10, 3639 (1998)
  3. A. Voigt, J. Richter, and P. Tomczak, "Low-lying excitations and thermodynamics of an antiferromagnetic Heisenberg fractal system of a dimension between one and two" , J. Magn. Magn. Mat. 183, 68 (1998)
  4. D.D. Betts, J. Schulenburg, G.E. Stewart, J. Richter, and J.S. Flynn, "Finite bcc lattices and their use in exact diagonalization of the S=1/2 Heisenberg antiferromagnet to estimate its T=0 properties on the inifinite lattice" J.Phys.A 31, 7685 (1998)
  5. H. Rosner, R. Hayn, J. Schulenburg, "Tight-binding parameters and exchange integrals of Ba2Cu3O4Cl2" , Physical Review B 57, 13660-13666 (1998)
  6. N.B. Ivanov, J. Richter, and U. Schollwöck, "Frustrated quantum Heisenberg ferrimagnetic chains" , Phys. Rev. B 58, 14456 (1998)

1997:

  1. D.J.J. Farnell, S.E. Krüger, J.B. Parkinson, "Coupled-cluster treatment of the XY-model" , J.Phys.: Condens.Matter 9, 7601 (1997)
  2. R. Hayn, A.F. Barabanov, J. Schulenburg, "Non-rigid hole band in the extended t-J model" , Z.Phys. B 102, 359 (1997)
  3. J. Schulenburg and J. Richter, "Ferromagnetic groundstate of two-band Hubbard model with one electron per site", acta physica polonica A 91, 367 (1997)
  4. J. Richter, S. Krüger, and N.B. Ivanov, "Order-disorder transition in a 2d Heisenberg quantum antiferromagnet with competing nearest neighbour bonds", Physica B 230-232, 1028 (1997)
  5. S. Krüger and J. Richter, "J1-J2-J3 model with long-range Lieb-Mattis interaction", acta physica polonica A 91, 377 (1997)
  6. J. Schulenburg and J. Richter, "Numerical study of the Goodenough-Kanamori-Anderson mechanism in a two-band Hubbard model", Physica B 230-232, 1044 (1997)
  7. A, Voigt and J. Richter, "Numerical study of weak ferromagnetism in 2d J1-J2 Heisenberg model with Dzyaloshinskii-Moriya interaction", acta physica polonica A 91, 371 (1997)
  8. N.B. Ivanov and J. Richter, "Competition between plaquette and dimer phases in Heisenberg chains" , Phys.Lett.A 232, 208 (1997)
  9. O. Derzhko and J. Richter, "A solvable model of a random spin-1/2- XY chain" , Phys. Rev. B 55, 14298 (1997)
  10. A. Voigt, J. Richter, and N.B. Ivanov, "Marshall-Peierls sign rule for excited states of the J1-J2 Heisenberg antiferromagnet" , Physica A 245, 269 (1997)
  11. K. Retzlaff, "Quantenfluktuationen in 2d Antiferromagneten - Analyse des Grundzustandes" Universität Magdeburg, Fakultät für Naturwissenschaften, Dissertation A, verteidigt am 21.07.1997, 90 Seiten

1996:

  1. N.B. Ivanov, S. Krüger and J. Richter, "Square-lattice Heisenberg antiferromagnet with two kinds of nearest neighbor regular bonds" , Phys. Rev. B 53, 2633 (1996)
  2. J. Richter, A. Voigt, S.E. Krüger, and C. Gros, "The spin 1/2 Heisenberg star with frustration II: The influence of the embedding medium" , J.Phys.A.: Math. Gen. 29, 825 (1996)
  3. P. Tomczak, A.R. Ferchmin, J. Richter, "Ground state of an antiferromagnetic Heisenberg spin system on a fractal lattice of dimension between one and two in Coherent Approaches to Fluctuations", eds. M.Suzuko and N.Kawashima, World Scientific 1996, p.284
  4. J. Richter, C. Gros, S. Krüger, W. Wenzel, and J. Schulenburg, "Phase transitions in two-layer spin 1/2 antiferromagnets with competing intra-layer and inter-layer couplings", J.Magn.Magn.Mat. 156, 433 (1996)
  5. R. Hayn, A.F. Barabanov, J. Schulenburg, and J. Richter, "The one-hole motion in the two-dimensional frustrated t-J model", Phys. Rev. B 53, 11714 (1996)
  6. A. Voigt and J. Richter, "The J1-J2 antiferromagnet with Dzyaloshinskii-Moriya interaction on the square lattice: An exact diagonalization study" , J.Phys. Condens. Matter , 8, 5059 (1996)
  7. J. Richter and N.B. Ivanov, "Zero-temperature quantum disorder in spin systems by competition between dimer and plaquette bonds", Proceedings of the LT21, Czech.J.Physics 46-S4, 1919 (1996)
  8. P. Tomczak, A.R. Ferchmin, J. Richter, "Ground state of an antiferromagnetic Heisenberg spin system on a non-translational lattice of dimension between one and two", Phys. Rev. B 54, 395 (1996)
  9. J. Richter, C. Gros, S.E. Krüger, and W. Wenzel, "Numerical versus exact results for coupled magnetic spin 1/2 layers" , J.Magn.Magn.Mat. 157/158, 336 (1996)
  10. P. Tomczak and J. Richter, "Thermodynamical properties of the Heisenberg antiferromagnet on the kagome lattice", Phys. Rev. B 54, 9004 (1996)
  11. O. Derzhko and J. Richter, "One variation on Lloyd's theme" , Phys. Lett.A 222, 338 (1996)

1995:

  1. C. Gros, W. Wenzel and J. Richter, "The transition from an ordered antiferromagnet to a quantum disordered spin liquid in a solvable bilayer model" , Europhys. Lett. 32 , 747 (1995)
  2. J. Richter, N.B. Ivanov, A. Voigt, and K. Retzlaff, "Ground-State Phase Relationships and Level Ordering for Frustrated Quantum Antiferromagnets", J. Low Temp. Phys. 99, 363 (1995)
  3. S. Feldkemper, W. Weber, J. Schulenburg, and J. Richter, "Ferromagnetism in nonmetallic Cu++ compounds", Phys. Rev. B 52, 313 (1995)
  4. A. Voigt, J. Richter, and S. Krüger, "The spin 1/2 Heisenberg star with frustration: Ground state and Thermodynamics" , J. Low Temp. Phys. 99, 381 (1995)
  5. N.B. Ivanov and J. Richter, "Spiral phase in easy plane J1-J2-J3 triangular antiferromagnets", J. Magn. Magn. Mat. 140-144, 1965 (1995)
  6. J. Richter, S. Krüger, A. Voigt und C. Gros, "A quantum spin model with two coupled subsystems: Exact solution for the linear chain and the Lieb-Mattis model", Physica B 206&207 , 119 (1995)
  7. J. Richter, N.B. Ivanov, and K. Retzlaff, "Indications for the breakdown of long-range order in the J1-J2 antiferromagnet on square lattice", J. Magn. Magn. Mat. 140-144 , 1609 (1995)
  8. K. Retzlaff and J. Richter, "Quantum Fluctuations in Structurally Disorderd Antiferromagnets", J. Low Temp. Phys. 99 , 359 (1995)
  9. J. Richter, A. Voigt, and S. Krüger, "A solvable quantum spin model: The frustrated Heisenberg star", J. Magn. Magn. Mat. 140-144 , 1497 (1995)
  10. J. Richter, N.B. Ivanov, K. Retzlaff, and A. Voigt, "Marshall-Peierls phase rule and Lieb-Mattis level ordering in non-bipartite low-dimensional antiferromagnets", J. Magn. Magn. Mat. 140-144 , 1611 (1995)

1994:

  1. J. Richter, S. Krüger, A. Voigt and C. Gros, "Integrable models of interacting quantum spins with competing interactions" , Europhys. Lett. 28 , 363 (1994)
  2. N.B. Ivanov und J. Richter, "J1-J2 quantum Heisenberg antiferromagnet: Improved spin-wave theories versus exact-diagonalization" , J.Phys.: Condens. Matter 6 , 3785 (1994)
  3. J. Richter, N.B. Ivanov und K. Retzlaff, "On the violation of Marshall-Peierls sign rule in the frustrated J1-J2 Heisenberg antiferromagnet" , Europhys. Lett. 25 , 545 (1994)
  4. J. Richter und A. Voigt, "The spin 1/2 Heisenberg star with frustration: Numerical versus exact results", J.Phys.A: Math. Gen. 27 , 1139 (1994)

1993:

  1. K. Retzlaff, J. Richter und N.B. Ivanov, "Analysis of the ground-state wave function of the J1-J2 model", Z.Phys.B 93 , 21 (1993)
  2. J. Richter, "Zero temperature magnetic ordering in the inhomogeneously frustrated quantum Heisenberg antiferromagnet on square lattice", Phys. Rev. B 47 , 5794 (1993)
  3. J. Richter, "Spin liquid properties of quantum spin systems", Proceedings of the International School of Condensed Matter Physics , Varna 1992, eds. J.M. Marshall, N.Kirov and A. Vavrek, World Scientific, 266 (1993)

1992:

  1. J. Richter C. Gros und W. Weber, "Reply to 'Comment on 'Chiral ordering in frustrated quantum spin system'' ", Phys. Rev. B 45, 10113 (1992)
  2. J. Richter, "The frustrated Heisenberg antiferromagnet: Collinear versus noncollinear magnetic ordering", J. Magn. Magn. Mat. 104-107 , 505 (1992)

1991:

  1. C. Gros, J. Richter und W. Weber, "Search for chiral order in frustrated quantum spin systems", Physica C 185-189 , 1481 (1991)
  2. J. Richter, C. Gros und W. Weber, "Chiral ordering in a frustrated quantum spin system", Phys. Rev. B 44 , 906 (1991)
  3. C. Gros und J. Richter, "Search for chiral ordering in frustrated quantum spin systems", Bulletin of the American Phys. Soc. 36 , 465 (1991)
home ITP Homepage back AG Homepage email RonaldQZinke@web.de