Group
Macroscopic systems and quantum theory
Recent publications and preprints
- 2015
- J. Richter, P. Müller, A. Lohmann, and H.-J. Schmidt,
High-temperature expansion for frustrated magnets: Application to the J1-J2 model on the BCC lattice,
Physics Procedia 75 (2015) 813-82ß0.
- H.-J. Schmidt, C. Schröder, E. Hägele, and M. Luban,
Dynamics and thermodynamics of a pair of interacting magnetic dipoles,
J. Phys. A: Math. Theor. 48 (2015) 185002.
- 2014
- H.-J. Schmidt, M. Imlau, and K.-M. Voit,
Explaining the success of Kogelnik’s coupled-wave
theory by means of perturbation analysis,
JOSA A 31, pp. 1158 - 1166 (2014).
- J. Richter, A. Lohmann, H.-J. Schmidt, and D.C. Johnston,
Magnetic susceptibility of frustrated spin-s J1-J2 quantum Heisenberg
magnets: High-temperature expansion and exact diagonalization data,
Paper presented at the 'XVII. International Conference on
Recent Progress in Many-Body Theories', Rostock Sept 2013, accepted for
publication in J. Phys. Conf. Ser
- A. Lohmann, H.-J. Schmidt, J. Richter,
Tenth-order high-temperature expansion for the susceptibility and the specific heat of spin-s
Heisenberg models with arbitrary exchange patterns: Application to pyrochlore and
kagome magnets,
Phys. Rev. B 89, 014415 (2014).
- 2013
- H.-J. Schmidt,
The general spin triangle,
Int. J. Mod. Phys. (2013), 27, vol. 16: 1350064
- 2012
- J. Richter and H.-J. Schmidt,
Exact ground state of a frustrated integer-spin modified
Shastry-Sutherland model,
Eur. Phys. J. B (2012), 85: 179
- 2011
- H.-J. Schmidt,
Erfahrungen mit "physics without lectures":
Bericht November 2011
Ankündigung Juli 2010:
Beispiele für Übungen:
Beispiele für Klausuren:
- H.-J. Schmidt, A. Lohmann, and J. Richter,
Eighth-order high-temperature expansion for general Heisenberg Hamiltonians
,
Phys. Rev. B 84, 104443 (2011).
- H.-J. Schmidt, Ch. Schröder, and M. Luban,
Modulated spin waves and robust quasi-solitons in classical Heisenberg rings,
J. Phys.: Condens. Matter 23 (2011) 386003.
- 2010
- H.-J. Schmidt and J. Richter,
Exact ground states for coupled spin trimers,
J. Phys. A: Math. Theor. 43 (2010) 405205.
- P. Busch and H.-J. Schmidt,
Coexistence of qubit effects,
Quantum Inf Process (2010) 9:143–169
- B. Erbe, H.-J. Schmidt,
Binary trees, coproducts, and integrable systems,
J. Phys. A: Math. Theor. 43 (2010) 085215
- 2009
- B. Hilling, T. Schemme, K.-M. Voit, H.-J. Schmidt, and M. Imlau,
Space-charge wave excitation by superposition of static and moving interference
patterns,
Phys. Rev. B 80 (2009) 205118
- T. Sauer and U. Majer (Eds.), in collaboration with A. Schirrmacher and H.-J. Schmidt,
David Hilbert's Lectures on the Foundations of Physics 1915-1927, Relativity, Quantum Theory and Epistemology
Springer, Dordrecht Heidelberg London New York, 2009, 795 p., Hardcover, ISBN: 978-3-540-20606-4
- R. Schnalle, A. Laeuchli, J. Schnack,
Approximate eigenvalue determination of geometrically frustrated magnetic molecules,
Condensed Matter Physics 12 (2009) 331
- R. Steinigeweg, J. Gemmer, H.-P. Breuer, H.-J. Schmidt,
Projection operator approach to transport in complex single-particle quantum systems,
Eur. Phys. J. B 69 (2009), p. 275-287
- R. Steinigeweg, H.-J. Schmidt,
Heisenberg-integrable spin systems,
Mathematical Physics, Analysis and Geometry 12, 1 (2009), p. 19-45
- R. Schnalle, J. Schnack,
Numerically exact and approximate determination of
energy eigenvalues for antiferromagnetic molecules using
irreducible tensor operators and general point-group
symmetries,
Phys. Rev. B 79 (2009) 104419
- J. Schnack, R. Schnalle,
Frustration effects in antiferromagnetic molecules: the
cuboctahedron,
Polyhedron 28 (2009) 1620-1623
- 2008
- K. Bärwinkel, J. Schnack,
Van Der Waals Revisited,
Physica A 387 (2008) 4581-4588
- J. Schnack, P. Hage, and H.-J. Schmidt, Efficient implementation of the Lanczos method for magnetic systems,
J. Comput. Phys. 227 (2008) 4512-4517
- 2007
- H.-J. Schmidt, Generalized Bell inequalities and frustrated spin systems,
submitted
- F. Ouchni, J. Schnack, J. Schulenburg,
Exact diagonalization of a one-dimensional Hubbard
model at density rho=0.4: Effects of Coulomb repulsions and
distant transfer,
Phys. Rev. B 76 (2007) 195106
- O. Derzhko, J. Richter, A. Honecker, and H.-J. Schmidt, Universal
properties of highly frustrated quantum magnets in strong magnetic fields,
Fizika Nizkikh Temperatur, v. 33, No.9 (2007), p. 982-996
Paper based on the invited talk given by J. Richter at the International
Conference "Statistical Physics 2006. Condensed Matter: Theory and Applications" dedicated to the 90th anniversary of Ilya Lifshitz (Kharkiv,
11-15 September, 2006)
- M. Allalen, T. Mehaddene, H. Bouzar,
Monte Carlo simulations of the L10 long-range order relaxation in dimensionally reduced systems,
J. Phys.: Condens. Mater. 19 (2007) 036218
- J. Schnack, R. Klingeler, V. Kataev, B. Büchner, Revisiting and modeling the magnetism of hole-doped
CuO2 spin chains in
Sr14-xCaxCu24O41,
J. Magn. Magn. Mater. 310 (2007) e397-e399
- J. Schnack,
Frustration-induced exotic properties of magnetic molecules,
C. R. Chimie 10 (2007) 15-20
- S. Torbrügge, J. Schnack, Sampling the two-dimensional density of states
g(E,M) of a giant magnetic molecule using the Wang-Landau
method,
Phys. Rev. B 75 (2007) 054403
- 2006
- 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. Confer. Ser. 51 (2006) 43
- J. Schnack,
Frustration effects in magnetic molecules,
J. Low. Temp. Phys. 142 (2006) 279-284
- H.-J. Schmidt, Johannes Richter, Roderich Moessner,
Linear independence of localized magnon states,
J. Phys. A: Math. Gen. 39 (2006) 10673-10690
- J. Schnack, P. Shchelokovskyy,
Solitary waves on finite-size antiferromagnetic quantum Heisenberg spin rings,
J. Magn. Magn. Mater. 306 (2006) 79-84
- R. Steinigeweg, H.-J. Schmidt,
Symplectic integrators for classical spin systems,
Comput. Phys. Comm. 174 (11), 853 (2006)
- M. Prinz, A. Takacs, J. Schnack, I. Balasz, E. Burzo,
U. Kortz, K. Kuepper, M. Neumann,
Magnetic and electronic properties of transition metal substituted, dimeric polyoxotungstates,
J. Appl. Phys. 99 (2006) 08J505
- M. Allalen, J. Schnack,
Theoretical estimates for proton-NMR spin lattice relaxation rates of heterometallic spin rings,
J. Magn. Magn. Mater. 302 (2006) 206-210
- J. Schnack, M. Brüger, M. Luban, P. Kögerler, E. Morosan, R. Fuchs, R. Modler, Hiroyuki Nojiri, Ram C. Rai, Jinbo Cao, J.L. Musfeldt, Xing Wei,
Observation of field-dependent magnetic parameters in the magnetic molecule {Ni4Mo12}
Phys. Rev. B 73 (2006) 094401
- R. Klingeler, B. Büchner, K.-Y. Choi, V. Kataev, U. Ammerahl, A. Revcolevschi, J. Schnack,
Revisiting the chain magnetism in Sr14Cu24O41: Experimental and numerical results,
Phys. Rev. B 73 (2006) 014426
- V. O. Garlea, S. E. Nagler, J. L. Zarestky, C. Stassis,
D. Vaknin, P. Kögerler, D. F. McMorrow, C. Niedermayer,
D. A. Tennant, B. Lake, Y. Qiu, M. Exler, J. Schnack, M. Luban,
Probing spin frustration in high-symmetry magnetic nanomolecules by inelastic neutron scattering,
Phys. Rev. B 73 (2006) 024414
- H.-J. Schmidt,
Einstein und die Quantentheorie,
in: Günther Abel (ed.): Kreativität,
Sektionsbeiträge des XX. Deutschen Kongresses für Philosophie, Band 1, Universitätsverlag der TU Berlin 2005, p. 731-736
- 2005
- M. Allalen, H. Bouzar, T. Mehaddene,
Saddle-point energies and Monte Carlo simulation of the long-range order relaxation in CoPt,
Eur. Phys. J. B 45 (2005) 443-448
- J. Schnack,
Strong Coulomb effects in hole-doped Heisenberg chains,
Eur. Phys. J. B 45 (2005) 311-315
- J. Schnack,
Quantum Theory of Molecular Magnetism,
Chapter of the proceedings of the IFF Spring School on Nanomagnetism 2005.
- C. Schröder, H.-J. Schmidt, J. Schnack, and M. Luban,
Metamagnetic phase transition of the antiferromagnetic Heisenberg icosahedron,
Phys. Rev. Lett. 94 (2005) 207203
- R. Schmidt, J. Richter, J. Schnack,
Frustration effects in magnetic molecules,
J. Magn. Magn. Mater. 295 (2005) 164-167
- H.-J. Schmidt,
Spin systems with dimerized ground states,
J. Phys. A: Math. Gen. 38 (2005) 2123-2143
- J. Schnack, F. Ouchni,
Exact diagonalization studies of doped Heisenberg spin rings,
J. Magn. Magn. Mater. 290-291 (2005) 341-344
- C. Schröder, H. Nojiri, J. Schnack, P. Hage, M. Luban, P. Kögerler,
Competing Spin Phases in Geometrically Frustrated Magnetic Molecules,
Phys. Rev. Lett. 94 (2005) 017205
- A. Postnikov, M. Brüger, J. Schnack,
Exchange interactions and magnetic anisotropy in the "Ni_4" magnetic molecule,
Phase Transitions 78 (2005) 47-59
- 2004
- J. Schnack,
Molecular Magnetism,
in Lecture Notes in Physics 645, Springer, Berlin,
Heidelberg (2004) 155-194
- D. P. Landau, Shan-Ho Tsai, and M. Exler,
A new approach to Monte Carlo simulations in statistical physics: Wang-Landau sampling,
Am. J. Phys. 72 (2004) 1294-1302
- A. Geisler, F. Homann, H.-J. Schmidt,
General properties and analytical approximations of photorefractive solitons,
Opt. Commun. 238 (2004) 351-361
- J. Schnack, Hiroyuki Nojiri, P. Kögerler, Geoffrey J. T. Cooper, Leroy Cronin,
Magnetic characterization of a novel frustrated three-leg ladder compound,
Phys. Rev. B 70 (2004) 174420
- H.-J. Schmidt, J. Bartke,
A solvable model of a one-dimensional quantum gas with pair interaction,
Physica A 335 (2004) 143-154
- C. Schröder, J. Schnack, D. Mentrup, M. Luban,
Critical slowing-down in classical and quantum Heisenberg magnetic molecules,
J. Magn. Magn. Mater. 272-276 (2004) e721-e723
- J. Richter, J. Schulenburg, A. Honecker, J. Schnack, H.-J. Schmidt,
Exact eigenstates and macroscopic magnetization
jumps in strongly frustrated spin lattices,
J. Phys.: Condens. Matter 16 (2004) S779-S784
- 2003
- K. Bärwinkel, P. Hage, H.-J. Schmidt, J. Schnack,
Quantum numbers for relative ground states of
antiferromagnetic Heisenberg spin rings,
Phys. Rev. B 68 (2003) 054422
- D. Mentrup, J. Schnack,
Nose-Hoover sampling of quantum entangled distribution functions,
Physica A 326 (2003) 370-383
- J. Schnack, M. Luban, R. Modler,
Rotational band structure of low-lying excitations in small Heisenberg systems,
Int. J. Mod. Phys. B 17 (2003) 5053-5057
- D. Mentrup, J. Schnack,
Isothermal quantum dynamics: Nose-Hoover method
for coherent states,
Int. J. Mod. Phys. B 17 (2003) 5449-5452
- D. Mentrup, M. Luban,
Almost-periodic wave packets and wave packets of
invariant shape,
Am. J. Phys. 71 (2003) 580
- K. Bärwinkel, H.-J. Schmidt, J. Schnack,
Improved upper and lower energy bounds for
antiferromagnetic Heisenberg spin systems,
Eur. Phys. J. B 33 (2003) 285-292
- H.-J. Schmidt, J. Schnack,
Symmetric polynomials in physics,
in: J.-P. Gazeau et al (eds.), GROUP 24,
Physical and Mathematical Aspects of Symmetries, Proceedings
of the 24th International Colloquium on Group Theoretical
Methods in Physics (Paris, July 15-20, 2002) , Institute of
Physics Conference Series No. 173 (2003), Institute of Physics
Publishing, Bristol and Philadelphia, p. 147-153
- H.-J. Schmidt, M. Luban,
Classical ground states of symmetrical Heisenberg spin systems,
J. Phys. A: Math. Gen. 36 (2003) 6351-6378
- M. Exler, J. Schnack,
Evaluation of the low-lying energy spectrum of
magnetic Keplerate molecules using the density-matrix renormalization group technique,
Phys. Rev. B 67 (2003) 094440
- 2002
- H.-J. Schmidt,
Structuralism in Physics,
The Stanford Encyclopedia of Philosophy (Winter
2002 Edition),
Edward N. Zalta (ed.)
- Marshall Luban, Ferdinando Borsa, Sergey Bud'ko, Paul
Canfield, Suckjoon Jun, Jae Kap Jung, Paul Kögerler,
Detlef Mentrup, Achim Müller, Robert Modler, Daniel Procissi, Byoung Jin Suh, and Milton Torikachvili,
Heisenberg spin triangles in {V6}-type magnetic molecules: Experiment and theory,
Phys. Rev. B 66 (2002) 054407
- H.-J. Schmidt,
Linear energy bounds for Heisenberg spin systems,
J. Phys. A: Math. Gen. 35 (2002) 6545-6555
- J. Schulenburg, A. Honecker, J. Schnack, J. Richter, H.-J. Schmidt,
Macroscopic magnetization jumps due to
independent magnons in frustrated quantum spin lattices,
Phys. Rev. Lett. 88 (2002) 167207
- H.-J. Schmidt, J. Schnack, M. Luban,
Reply to the Comment by O. Waldmann on "Bounding and approximating parabolas for the
spectrum of Heisenberg spin systems",
Europhysics Letters 57 (2002) 620
- H.-J. Schmidt, J. Schnack,
Partition functions and symmetric polynomials,
Am. J. Phys. 70 (2002) 53-57
- 2001
- J. Schnack, H.-J. Schmidt, J. Richter, J. Schulenburg,
Independent magnon states on magnetic polytopes,
Eur. Phys. J. B 24 (2001) 475
- J. Schnack, M. Luban, R. Modler,
Quantum rotational band model for the
Heisenberg molecular magnet Mo_72Fe_30,
Europhysics Letters 56 (2001) 863
- D. Mentrup, J. Schnack,
Isothermal quantum dynamics: Nos\'e-Hoover method
for coherent states,
in Advances in Quantum Many-Body Theory,
Proceedings of
"The 11th International Conferences on Recent Progress in Many-Body
Theories", Manchester,
edited by Raymond F. Bishop, Tobias Brandes, Klaus A. Gernoth, Niels R. Walet, and
Yang Xian (UMIST, Manchester, UK, 2001),
World Scientific
- J. Schnack, M. Luban, R. Modler,
Rotational band structure of low-lying excitations in small Heisenberg systems,
in Advances in Quantum Many-Body Theory,
Proceedings of
"The 11th International Conferences on Recent Progress in Many-Body
Theories", Manchester,
edited by Raymond F. Bishop, Tobias Brandes, Klaus A. Gernoth, Niels R. Walet, and
Yang Xian (UMIST, Manchester, UK, 2001),
World Scientific
- H.-J. Schmidt, J. Schnack, M. Luban,
Heisenberg exchange parameters of molecular magnets from
the high-temperature susceptibility expansion,
Phys. Rev. B 64 (2001) 224415
- A. Müller, M. Luban, C. Schröder, R. Modler,
P. Kögerler, M. Axenovich, J. Schnack, P.C. Canfield,
S. Bud'ko, and Neil Harrison,
Classical and Quantum Magnetism in Giant Keplerate Magnetic Molecules,
Chem. Phys. Chem. 2 (2001) 517
- D. Mentrup, J. Schnack,
Nose-Hoover dynamics for coherent states,
Physica A 297 (2001) 337-347
- H.-J. Schmidt, J. Schnack, M. Luban,
Bounding and approximating parabolas for the spectrum of Heisenberg spin systems,
Europhysics Letters 55 (2001) 105-111
- A. Pop, A. Andronic, I. Berceanu, M. Duma, D. Mois,
M. Petrovici, V. Simion, A. Bonasera, G. Immé,
G. Lanzanò, A. Pagano, G. Raciti, N. Colonna,
G. d'Erasmo, A. Pantaleo, H. Feldmeier, and
J. Schnack,
Global features of dissipative processes in light heavy-ion collisions,
Nucl. Phys. A 679 (2001) 793-823
- H.-J. Schmidt, M. Luban,
Continuous families of isospectral Heisenberg
spin systems and the limits of inference from
measurements,
J. Phys. A: Math. Gen. 34 (2001) 2839-2858
- J. Schnack, M. Luban,
Rotational modes in molecular magnets with
antiferromagnetic Heisenberg exchange,
Phys. Rev. B 63 (2001) 014418
- 2000
- J. Schnack,
Properties of the first excited state of
nonbipartite Heisenberg spin rings,
Phys. Rev. B 62 (2000) 14855-14859
- H.-J. Schmidt,
Is there a gravitational collaps of the wave-packet?,
in "Trends in Quantum Mechanics", ed. by
H.-D. Doebner, S.T. Ali, M. Keyl and R.F. Werner,
World Scientific, Singapore (2000) 122-129
- H.-J. Schmidt, F. Homann,
Photon Stars,
General Relativity and Gravitation (GRG)
Vol. 32, No. 5 (May 2000) 919 - 931
- H. Feldmeier, J. Schnack,
Molecular Dynamics for Fermions,
Rev. Mod. Phys. 72 (2000) 655-688
- K. Bärwinkel, H.-J. Schmidt, J. Schnack,
Ground state properties of antiferromagnetic
Heisenberg spin rings,
Journal of Magnetism and Magnetic Materials 220 (2000) 227
- D. Mentrup, H.-J. Schmidt, J. Schnack, M. Luban,
Transition from quantum to classical Heisenberg
trimers: Thermodynamics and time correlation
functions,
Physica A 278 (2000) 214-221
- Y. Furukawa, M. Luban, F. Borsa, D.C. Johnston,
A.V. Mahajan, L.L. Miller, D. Mentrup, J. Schnack,
A. Bino,
Spin dynamics of the magnetic cluster [Cr_4S(O_2CCH_3)_8(H_2O)_4](NO_3)_2H_2O,
Phys. Rev. B 61 (2000) 8635
- K. Bärwinkel, H.-J. Schmidt, J. Schnack,
Structure and relevant dimension of the
Heisenberg model and applications to spin rings,
Journal of Magnetism and Magnetic Materials 212
(2000) 240-250
- 1999
- D. Mentrup, J. Schnack, M. Luban,
Spin dynamics of quantum and classical Heisenberg dimers,
Physica A 272 (1999) 153-161
- J. Schnack,
Thermodynamics of the harmonic oscillator using coherent states,
Europhysics Letters 45 (1999) 647-652
- H.-J. Schmidt, J. Schnack,
Thermodynamic fermion-boson symmetry in harmonic oscillator potentials,
Physica A 265 (1999) 584-589
- K. Bärwinkel, J. Schnack, U. Thelker,
Quasi-Particle Picture for Monatomic Gases,
Physica A 262 (1999) 496-504
- J. Gerling, H.-J. Schmidt,
Three-Term Asymptotics of the Spectrum of Self-Similar Fractal Drums,
Journal of Mathematical Sciences Vol. 6, No. 1,
University of Tokyo
(1999) 101
- K. Bärwinkel, H.-J. Schmidt, J. Schnack,
On cyclically shifted strings,
unpublished
- T. Neff, H. Feldmeier, R. Roth, J. Schnack,
Realistic interactions and configuration mixing in
Fermionic Molecular Dynamics,
Multifragmentation, Proc. Int. Workshop XXXVII,
Hirschegg (1999) 283--292, ISSN 0720-8715
- 1998
- H.-J. Schmidt, J. Schnack,
Investigations on finite ideal quantum gases,
Physica A 260 (1998) 479-489
- J. Schnack,
Molecular dynamics investigations on a quantum system in a thermostat,
Physica A 259 (1998) 49-58
- H. Feldmeier, T. Neff, R. Roth, J. Schnack,
A unitary correlation operator method,
Nucl. Phys. A632 (1998) 61-95
- H. Feldmeier, T. Neff, R. Roth, J. Schnack,
Fermionic Molecular Dynamics and short range correlations,
Proceedings of the
"XVII RCNP International Symposium on Innovative
Computational Methods in Nuclear Many-Body Problems",
Osaka, World Scientific (1998)
- H. Feldmeier, J. Schnack,
Liquid-gas phase transition in finite nuclei
within Fermionic Molecular Dynamics,
Proceedings of the "Workshop on Nuclear Matter
in Different Phases and Transitions",
Les Houches, France,
Kluwer Academic Publ. in
Fundamental Theories of Physics (1998)
You may find more publications on the personal web sites of the
group members.
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