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Prof. Dr. Thomas Lorenz

Contact

Phone : +49-221-470-3593

Fax:      +49-221-470-6708

Room:    223

e-mail:   lorenz@ph2.uni-koeln.de

Research

  • thermodynamic and transport propoerties of correlated electron systems
  • low dimensional magnetism and quantum spin systems
  • (unconventional) superconductors
  • interplay of charge, spin, lattice and orbital degrees of freedom
  • transiton metal oxides
  • single crystal growth

Scientific career

Apl. Professor:

May 2015, University of Cologne

Habilitation:

January 2010, University of Cologne

Anomalous Behavior of Spin Liquids: Thermodynamics and Heat Transport

Post-Doc:

October 1999 until September 2002: Scientific Assistant at the Institute of Physics II,  University of Cologne

October 1998 until September 1999: Post-Doc in the Oxide Spin Electronic Network (OXSEN) at the Laboratoire de l'Etat Solide and the Institut d'Electronique Fondamentale, Universite Paris-Sud, France. Research field: single crystal growth and studies of the magnetotransport properties of doped rare earth manganites and cobaltates.

PhD:

July 1998, University of Cologne

Thesis: Thermodynamische Eigenschaften des Spin-Peierls-Systems CuGeO3 (ISBN 3-8265-4179-0)

Referees: Prof. Dr. R. Gross, Prof. Dr. A. Freimuth & Prof. Dr. A Klümper

 

Diploma:

July 1994, University of Cologne

Thesis: Aufbau eines Magnetkryostaten und Messungen der thermischen Ausdehnung von La1.87Sr0.13CuO4 im transversalen Magnetfeld

Referees: Prof. Dr. H. Micklitz, Prof. Dr. E. Müller-Hartmann

University studies:

1990-1994 University of Cologne, Germany

1989-1990 University of Vienna, Austria

1987-1989 University of Freiburg, Germany

Publications

Zhe Wang and T. Lorenz and D.I. Gorbunov and P.T. Cong and Y. Kohama and S. Niesen and O. Breunig and J. Engelmayer and A. Herman and Jianda Wu and K. Kindo and J. Wosnitza and S. Zherlitsyn and A. Loidl
Quantum Criticality of an Ising-like Spin-1/2 Antiferromagnetic Chain in a Transverse Magnetic Field
Phys. Rev. Lett., 120, 207205, 2018, arXiv:1805.02392

Lionel Andersen and Zhiwei Wang and Thomas Lorenz and Yoichi Ando
Nematic Superconductivity in Cu$_{1.5}$(PbSe)$_{5}(Bi$_{2}Se$_{3})$_{6}
, Phys. Rev. B, 2018, arXiv:1811.00805

Lionel Andersen and Zhiwei Wang and Thomas Lorenz and Yoichi Ando
Nematic Superconductivity in Cu$_{1.5}$(PbSe)$_{5}$(Bi$_{2}$Se$_{3}$)$_{6}$
Phys. Rev. B, 98, 220512(R), 2018, arXiv:1811.00805, PDF (554kB)

Q. Faure and S. Takayoshi and S. Petit and V. Simonet and S. Raymond and L.-P. Regnault and M. Boehm and J.S. White and M. Mansson and Ch. Rüegg and P. Lejay and B. Canals and T. Lorenz and S.C. Furuya and T. Giamarchi and B. Grenier
Topological quantum phase transition in the Ising-like antiferromagnetic spin chain BaCo2V2O8
Nature Physics, 14, 716, 2018, arXiv:1706.05848

Carl Rischau and Xiao Lin and Christoph Grams and Dennis Finck and Steffen Harms and Johannes Engelmayer and Thomas Lorenz and Yann Gallais and Benoit Fauqué and Joachim Hemberger and Kamran Behnia
A ferroelectric quantum phase transition inside the superconducting dome of Sr1-xCaxTiO3-δ
Nature Physics, 13, 643, 2017, http://www.nature.com/articles/nphys4085.epdf

Oliver Breunig and Markus Garst and Andreas Klümper and Jens Rohrkamp and Mark M. Turnbull and Thomas Lorenz
Quantum criticality in the spin-1/2 Heisenberg chain system copper pyrazine dinitrate
Sci Adv, 3, eaao3773, 2017, arXiv:1709.00274

S. Kunkemöller and D. Brüning and A. Stunault and A.A. Nugroho and T. Lorenz and M. Braden
Magnetic shape-memory effect in SrRuO$_3$
Phys. Rev. B, 96, 220406(R), 2017, arXiv:1709.05688, PDF (5064kB)

S. Holbein and M. Ackermann and L. Chapon and P. Steffens and A. Gukasov and A. Sazonov and O. Breunig and Y. Sanders and P. Becker and L. Bohaty and T. Lorenz and M. Braden
Strong magnetoelastic coupling at the transition from harmonic to anharmonic order in NaFe(WO4)2 with 3d5 configuration
Phys. Rev. B, 94, 104423, 2016, arXiv:1609.01849, PDF (4648kB)

S. Scharffe and G. Kolland and M. Valldor and V. Cho and J.F. Welter and T. Lorenz
Heat transport of the spin-ice materials Ho2Ti2O7 and Dy2Ti2O7
J. Magn. Magn. Mater., 383, 83, 2015, http://authors.elsevier.com/a/1QoI315Kgari1c, arXiv:1406.4037, PDF (620kB)

M. Ackermann and L. Andersen and T. Lorenz and L. Bohaty and P. Becker
Anisotropy study of multiferroicity in the pyroxene NaFeGe2O6
New J. Phys., 17, 013045, 2015, arXiv:1408.6772, PDF (8059kB)

O. Breunig and M. Garst and A. Rosch and E. Sela and B. Buldmann and P. Becker and L. Bohaty and R. Müller and T. Lorenz
Low-temperature ordered phases of the spin-1/2 XXZ chain system Cs2CoCl4
Phys. Rev. B, 91, 024423, 2015, arXiv:1412.2988, PDF (1315kB)

S. Scharffe and O. Breunig and V. Cho and P. Laschitzky and M. Valldor and J. F. Welter and T. Lorenz
Suppression of Pauling's residual entropy in the dilute spin ice (Dy_(1-x)Y_x )2Ti2O7
Phys. Rev. B, 92, 180405(R), 2015, arXiv:1503.03856, PDF (576kB)

C. Ulrich and G. Khaliullin and M. Guennou and H. Roth and T. Lorenz and B. Keimer
Spin-orbital excitation continuum and anomalous electron-phonon interaction in the Mott insulator LaTiO$_3$
Phys. Rev. Lett., 115, 156403, 2015, arXiv:1509.05280, PDF (710kB)

P. Toledano and M. Ackermann and L. Bohaty and P. Becker and T. Lorenz and N. Leo and M. Fiebig
Primary ferrotoroidicity in antiferromagnets
Phys. Rev. B, 92, 094431, 2015, PDF (651kB)

S. K. Niesen and O. Breunig and S. Salm and M. Seher and M. Valldor and T. Lorenz
Substitution effects on the temperature vs. magnetic-field phase diagrams of the quasi-1D effective Ising spin-1/2 chain system BaCo2V2O8
Phys. Rev. B, 90, 104419, 2014, arXiv:1405.7273, PDF (1502kB)

S. Scharffe and G. Kolland and M. Hiertz and M. Valldor and T. Lorenz
Hysteresis and Relaxation Effects in the Spin-Ice Compound Dy2Ti2O7 studied by Heat Transport
JPS Conf. Proc., 3, 014030, 2014, arXiv:1311.1139, PDF (632kB)

M. Ackermann and T. Lorenz and L. Bohaty and P. Becker
Magnetoelectric properties of A2[FeCl5(H2O)] with A = K, Rb, Cs
J. Phys.: Condens. Matter, 26, 506002, 2014, arXiv:1408.3997, PDF (1116kB)

G. Kolland and M. Valldor and M. Hiertz and J. Frielingsdorf and T. Lorenz
Anisotropic Monopole Heat Transport in the Spin-Ice Compound Dy$_2$Ti$_2$O$_7$
Phys. Rev. B, 88, 054406, 2013, arXiv:1302.6114, PDF (450kB)

S. K. Niesen and G. Kolland and M. Seher and O. Breunig and M. Valldor and M. Braden and B. Grenier and T. Lorenz
Magnetic phase diagrams, domain switching and a quantum phase transition of the quasi-1D Ising-like antiferromagnet BaCo2V2O8
Phys. Rev. B, 87, 224413, 2013, arXiv:1303.5599, PDF (3234kB)

M. Ackermann and D. Brüning and T. Lorenz and P. Becker and L.Bohaty
Thermodynamic properties of the new multiferroic material (NH4)2[FeCl5(H2O)]
New J. Phys., 15, 123001, 2013, PDF (3997kB)

O. Breunig and M. Garst and E. Sela and B. Buldmann and P. Becker and L. Bohaty and R. Müller and T. Lorenz
The spin-1/2 XXZ chain system Cs2 CoCl4 in a transverse magnetic field
Phys. Rev. Lett., 111, 187202, 2013, arXiv:1307.2870, PDF (334kB)

A C. Komarek and M. Reuther and T. Lorenz and A. Cousson and P. Link and W. Morgenroth and D. Trots and C. Baehtz and M. Braden
Evidence for charge and orbital order in the doped titanates RE(1-x)CaxTiO3 (RE=Y, Er, Lu)
, Phys. Rev. Lett., 2012, arXiv:1109.0234

G. Kolland and O. Breunig and M. Valldor and M. Hiertz and J. Frielingsdorf and T. Lorenz
Thermal conductivity and specific heat of the spin-ice compound Dy2 Ti2 O7 : Experimental evidence for monopole heat transport
Phys. Rev. B, 86, 060402(R), 2012, arXiv:1205.5700, PDF (358kB)

Z. Hu and Hua Wu and T.C. Koethe and S.N. Barilo and S.V. Shiryaev and G.L. Bychkov and C. Schüßler-Langeheine and T. Lorenz and A. Tanaka and H.H. Hsieh and H-J. Lin and C.T. Chen and N.B. Brookes and S. Agrestini and Y-Y. Chin and M. Rotter and L.H. Tjeng
Spin-state order/disorder and metal insulator transition in GdBaCo$_2$O$_{5.5}$: experimental determination of the underlying electronic structure
New J. Phys., 14, 123025, 2012

G. Giovannetti and A. Stroppa and S. Picozzi and D. Baldomir and V. Pardo and S. Blanco-Canosa and F. Rivadulla and S. Jodlauk and D. Niermann and J. Rohrkamp and T. Lorenz and S. Streltsov and D.I. Khomskii and J. Hemberger
Dielectric properties and magnetostriction of the collinear multiferroic spinel CdV2O4
Phys. Rev. B, 83, 060402(R), 2011

M. Valldor and O. Heyer and A. C. Komarek and A. Senyshyn and M. Braden and T. Lorenz
Magnetostrictive Neel ordering of the spin-5/2 ladder compound BaMn2O3: Distortion-induced lifting of geometrical frustration
Phys. Rev. B, 83, 024418, 2011, arXiv:1010.1183, PDF (897kB)

S.K.Niesen and O. Heyer and T. Lorenz and M. Valldor
Antiferromagnetic Heisenberg S=5/2 spin chain compound SrMn2V2O8
J. Magn. Magn. Mater., 323, 2575, 2011, arXiv:1103.1830

N. Hollmann and M. W. Haverkort and M. Benomar and M. Cwik and M. Braden and T. Lorenz
Evidence for a temperature-induced spin-state transition of Co3+ in La2-xSrxCoO4
Phys. Rev. B, 83, 174435, 2011, arXiv:1204.0730, PDF (377kB)

A. C. Komarek and M. Isobe and J. Hemberger and D. Meier and T. Lorenz and D. Trots and A. Cervellino and M. T. Fernández-Díaz and Y. Ueda and M. Braden
Dimerization and Charge Order in Hollandite K2V8O16
Phys. Rev. Lett., 107, 027201, 2011

M. K. Forthaus and G. R. Hearne and N. Manyala and O. Heyer and R. A. Brand and D. I. Khomskii and T. Lorenz and M. M. Abd-Elmeguid
Pressure-induced quantum phase transition in Fe1−xCoxSi (x = 0.1,0.2)
Phys. Rev. B, 83, 085101, 2011, PDF (1294kB)

O. Heyer and T. Lorenz and V. B. Zabolotnyy and D. V. Evtushinsky and S. V. Borisenko and I. Morozov and L. Harnagea and S. Wurmehl and C. Hess and B. Büchner
Resistivity and Hall effect of LiFeAs: Evidence for electron-electron scattering
Phys. Rev. B, 84, 064512, 2011, arXiv:1010.2876, PDF (355kB)

O. Heyer and P. Link and D. Wandner and U Ruschewitz and T. Lorenz
Thermodynamic properties and resistivity of the ferromagnetic semiconductor EuC2
New J. Phys., 13, 113041, 2011, arXiv:1103.0980, PDF (752kB)

A.V. Kalinov and O.Yu. Gorbenko and A.N. Taldenkov and J. Rohrkamp and O. Heyer and S. Jodlauk and N.A. Babushkina and L.M. Fisher and A.R. Kaul and D.I. Khomskii and K.I. Kugel and T. Lorenz
Phase Diagram of Spin States and Magnetic Interactions in Isotope Substituted (Pr,Eu)0.7Ca0.3CoO3
Solid State Phenomena, 168-169, 465, 2011, PDF (215kB)

H. Banks and N. J. Hillier and J. S. Schilling and J. Rohrkamp and T. Lorenz and J. A. Mydosh and T. Fickenscher and R. Pöttgen
Dependence of the magnetic ordering temperature on hydrostatic pressure for the ternary intermetallic compounds GdAgMg, GdAuMg, EuAgMg, and EuAuMg
Phys. Rev. B, 81, 212403, 2010, PDF (388kB)

A. V. Kalinov and O. Yu. Gorbenko and A. N. Taldenkov and J. Rohrkamp and O. Heyer and S. Jodlauk and N. A. Babushkina and L. M. Fisher and A. R. Kaul and A. A. Kamenev and T. G. Kuzmova and D. I. Khomskii and K. I. Kugel and T. Lorenz
Phase diagram and isotope effect in (Pr1−yEuy)0.7Ca0.3CoO3 cobaltites exhibiting spin-state transitions
Phys. Rev. B, 81, 134427, 2010, arXiv:0909.2978, PDF (891kB)

Sina Zimmermann and Matthias Brühmann and Frederick Casper and Oliver Heyer and Thomas Lorenz and Claudia Felser and Anja-Verena Mudring and Gerd Meyer
Eight-Coordinate Endohedral Rhenium, Osmium and Iridium Atoms in Rare- Earth Halide Cluster Complexes
Eur. J. Inorg. Chem., 18, 2613, 2010, PDF (832kB)

J. Rohrkamp and M.D. Phillips and M.M. Turnbull and T. Lorenz
Thermal expansion of the spin-1/2 Heisenberg-chain compound Cu(C4H4N2)(NO3)2
JPCS, 200, 012169, 2010, arXiv:0907.0400, PDF (4985kB)

N. A. Babushkina and A. N. Taldenkov and A. V. Kalinov and L. M. Fisher and O. Yu. Gorbenko and T. Lorenz and D. I. Khomskii and K. I. Kugel
Isotope Effect and Characteristic Features of the Phase Diagram for Cobaltites with Spin State Transitions
JETP, 111, 189, 2010, PDF (220kB)

M. K. Forthaus and K. Sengupta and O. Heyer and N. E. Christensen and A. Svane and K. Syassen and D. I. Khomskii and T. Lorenz and M. M. Abd-Elmeguid
Superconductivity in SnO: A Nonmagnetic Analog to Fe-Based Superconductors?
Phys. Rev. Lett., 105, 157001, 2010, arXiv:1009.3787

A. Senyshyn and B. Schwarz and T. Lorenz and V. T. Adamiv and Ya. V. Burak and J. Banys and R. Grigalaitis and L. Vasylechko and H. Ehrenberg and H. Fuess
Low-temperature crystal structure, specific heat, and dielectric properties of lithium tetraborate Li2B4O7
J. Appl. Phys., 108, 093524, 2010, PDF (490kB)

Chun Fu Chang and Zhiwei Hu and Hua Wu and Tobias Burnus and N. Hollmann and Mohamed Benomar and T. Lorenz and Arata Tanaka and Hong-Ji Lin and H. H. Hsieh and C. T. Chen and L. Hao Tjeng
Spin blockade, orbital occupation, and charge ordering in La1.5Sr0.5CoO4
Phys. Rev. Lett., 102, 116401 (An Editors' Suggestion), 2009, arXiv:0901.3642

M. Cwik and M. Benomar and T. Finger and Y. Sidis and D. Senff and M. Reuther and T. Lorenz and M. Braden
Magnetic Correlations in La2-xSrxCoO4 Studied by Neutron Scattering: Possible Evidence for Stripe Phases
Phys. Rev. Lett., 102, 057201, 2009, arXiv:0808.0106, PDF (585kB)

A. V. Sologubenko and T. Lorenz and J. A. Mydosh and B. Thielemann and H. M. Rønnow and Ch. Rüegg and K. W. Krämer
Evidence for spinon localization in the heat transport of the spin-1 2 ladder compound (C5H12N)2CuBr4
Phys. Rev. B, 80, 220411(R), 2009, arXiv:0909.5180, PDF (245kB)

M. Kriener and M. Braden and H. Kierspel and D. Senff and O. Zabara and C. Zobel and T. Lorenz
Magnetic and structural transitions in La1−xAxCoO3 (A=Ca, Sr, and Ba)
Phys. Rev. B, 79, 224104, 2009, arXiv:0801.4188, PDF (1820kB)

C. Ulrich and L. J. P. Ament and G. Ghiringhelli and L. Braicovich and M. Moretti Sala and N. Pezzotta and T. Schmitt and G. Khaliullin and J. van den Brink and H. Roth and T. Lorenz and B. Keimer
Momentum Dependence of Orbital Excitations in Mott-Insulating Titanates
Phys. Rev. Lett., 103, 107205, 2009, arXiv:0908.2497, PDF (298kB)

N. Hollmann and M. W. Haverkort and M. Cwik and M. Benomar and M. Reuther and A. Tanaka and T. Lorenz
Anisotropic Susceptibility of La2-xSrxCoO4 related to the spin states of cobalt
New J. Phys., 10, 023018, 2008, arXiv:0801.2087

F. Anfuso and M. Garst and A. Rosch and O. Heyer and T. Lorenz and Ch. Rüegg and K. Krämer
Spin-spin correlations of the spin-ladder compound (C5H12N)2CuBr4 measured by magnetostriction and comparison to Quantum Monte Carlo results
Phys. Rev. B, 77, 212102, 2008, arXiv:0803.1072, PDF (829kB)

D. Bichler and V. Zinth and D. Johrendt and O. Heyer and M.K. Forthaus and T. Lorenz and M.M. Abd-Elmeguid
Structural and magnetic phase transitions of the V4-cluster compound GeV4S8
Phys. Rev. B, 77, 212102, 2008, PDF (282kB)

D. Senff and O. Schumann and M. Benomar and M. Kriener and T. Lorenz and Y. Sidis and K. Habicht and P. Link and M. Braden
Melting of magnetic correlations in charge-orbital ordered La1/2Sr3/2MnO4: competition of ferro and antiferromagnetic states
Phys. Rev. B, 77, 184413, 2008, arXiv:0801.1787, PDF (757kB)

A.V. Sologubenko and K. Berggold and T. Lorenz and A. Rosch and E. Shimshoni and M.D. Phillips and M.M. Turnbull
Magnetic field-dependent thermal transport in a spin-1/2 chain compound
Physica B, 403, 1445, 2008

C. Ulrich and G. Ghiringhelli and A. Piazzalunga and L. Braicovich and N.B. Brookes and H. Roth and T. Lorenz and B. Keimer
Orbital excitations in YTiO3 and LaTiO3 probed by resonant inelastic soft x-ray scattering
Phys. Rev. B, 77, 113102, 2008, PDF (242kB)

A.V. Sologubenko and T. Lorenz and J.A. Mydosh and A. Rosch and K.C. Shortsleeves and M.M. Turnbull
Field-dependent thermal transport in the Haldane chain compound NENP
Phys. Rev. Lett., 100, 137202, 2008, arXiv:0712.3991, PDF (304kB)

T. Lorenz and O. Heyer and M. Garst and F. Anfuso and A. Rosch and Ch. Rüegg and K. Krämer
Diverging thermal expansion of the spin-ladder system (C5H12N)2CuBr4
Phys. Rev. Lett., 100, 067208, 2008, arXiv:0711.1510, PDF (712kB)

A. Gössling and R. Schmitz and H. Roth and M.W. Haverkort and T. Lorenz and J.A. Mydosh and E. Müller-Hartmann and M. Grüninger
Mott-Hubbard exciton in the optical conductivity of YTiO3 and SmTiO3
Phys. Rev. B, 78, 075122, 2008, arXiv:cond-mat/0608531, PDF (378kB)

N. Johannsen and S. Süllow and A.V. Sologubenko and T. Lorenz and J.A. Mydosh
Magneto-thermal evidence of a partial gap at the Fermi surface of UPt2Si2
Phys. Rev. B, 78, 121103(R), 2008, arXiv:0804.1318, PDF (275kB)

K. Berggold and M. Kriener and P. Becker and M. Benomar and M. Reuther and C. Zobel and T. Lorenz
Anomalous expansion and phonon damping due to the Co spin-state transition in RCoO3 (R=La, Pr, Nd, and Eu)
Phys. Rev. B, 78, 134402, 2008, arXiv:0803.1957, PDF (687kB)

I. Loa and X. Wang and K. Syassen and H. Roth and T. Lorenz and M. Hanfland and Y.-L. Mathis
Crystal structure and the Mott–Hubbard gap in YTiO3 at high pressure
J. Phys.: Condens. Matter, 19, 406223, 2007, arXiv.org:condmat/0504383, PDF (610kB)

A. C. Komarek and H. Roth and M. Cwik and W.-D. Stein and J. Baier and M. Kriener and F. Bourée and T. Lorenz and M. Braden
Magnetoelastic coupling in RETiO3 (RE = La, Nd, Sm, Gd, Y) investigated with diffraction techniques and thermal expansion measurements
Phys. Rev. B, 75, 224402, 2007, arXiv.org:cond-mat/0701452, PDF (863kB)

M.W. Haverkort and Z. Hu and J.C. Cezar and T. Burnus and H. Hartmann and M. Reuther and C. Zobel and T. Lorenz and A. Tanaka and N.B. Brookes and H.H. Hsieh and H.-J. Lin and C.T. Chen and L.H. Tjeng
Spin state transition in LaCoO3 studied using soft X-ray absorption spectroscopy and magneic circular dichrosim
, , , 2007, PDF (312kB)

D. Meier and N. Aliouane and D.N. Argyriou and J.A. Mydosh and T. Lorenz
New features in the phase diagram of TbMnO3
New J. Phys., 9, 100, 2007, arXiv.org:cond-mat/0701487, PDF (976kB)

J. Rohrkamp and O. Heyer and T. Fickenscher and R. Pöttgen and S. Jodlauk and H. Hartmann and T. Lorenz and J.A. Mydosh
Thermal expansion of the magnetically ordering intermetallics RTMg (R = Eu, Gd and T = Ag, Au)
J. Phys.: Condens. Matter, 19, 486204, 2007, arXiv:0708.2817v1, PDF (493kB)

K. Berggold and J. Baier and D. Meier and J.A. Mydosh and T. Lorenz and J. Hemberger and A. Balbashov and N. Aliouane and D.N. Argyriou
Anomalous thermal expansion and strong damping of the thermal conductivity of NdMnO3 and TbMnO3 due to 4f crystal-field excitations
Phys. Rev. B, 76, 094418, 2007, arXiv:cond-mat/0703222, PDF (529kB)

S. Jodlauk and P. Becker and J. A. Mydosh and D. I. Khomskii and T. Lorenz and S. V. Streltsov and D. C. Hezel and L. Bohaty
Pyroxenes: A new class of multiferroics
J. Phys.: Condens. Matter, 19, 432201, 2007, arXiv:0709.1125, PDF (975kB)

N. Johannsen and Th. Wolf and A.V. Sologubenko and T. Lorenz and A. Freimuth and J.A. Mydosh
Nernst Effect in NdBa2[Cu1-yNiy]3O7-δ
Phys. Rev. B, 76, 020512(R), 2007, arXiv:0706.1463, PDF (417kB)

T. Lorenz and S. Stark and O. Heyer and N. Hollmann and A. Vasiliev and A. Oosawa and H. Tanaka
Thermodynamics of the coupled spin-dimer system TlCuCl3 close to a quantum phase transition
J. Magn. Magn. Mater., 316, 291, 2007, arXiv:cond-mat/0609348), PDF (531kB)

R. Lengsdorf and J.-P. Rueff and G. Vanko and T. Lorenz and L. H. Tjeng and M. M. Abd-Elmeguid
Spin-state-driven metal-insulator transition in (La,Sr)CoO3 under high-pressure
Phys. Rev. B, 75, 180401(R), 2007, PDF (176kB)

J. Baier and P. Steffens and O. Schumann and M. Kriener and S. Stark and H. Hartmann and O. Friedt and A. Revcolevschi and P.G. Radaelli and S. Nakatsuji and Y. Maeno and J.A. Mydosh and T. Lorenz and M. Braden
Magnetoelastic coupling across the metamagnetic transition in Ca2-xSrxRuO4 (0.2 ≤ x ≤ 0.5)
J. Low Temp. Phys., 147, 405, 2007, arXiv:cond-mat/0610769

A.V. Sologubenko and T. Lorenz and H.R. Ott and A. Freimuth
Thermal conductivity via magnetic excitations in spin-chain materials
J. Low Temp. Phys., 147, 387, 2007, arXiv:cond-mat/0611052

J. Baier and D. Meier and K. Berggold and J. Hemberger and A. Balbashov and J.A. Mydosh and T. Lorenz
Uniaxial pressure dependencies of the phase transitions in GdMnO3
J. Magn. Magn. Mater., 310, 1165, 2007, arXiv:cond-mat/0605515

A.V. Sologubenko and K. Berggold and T. Lorenz and A. Rosch and E. Shimshoni and M.D. Phillips and M.M. Turnbull
Magnetothermal transport in the spin-1/2 chains of copper pyrazine dinitrate
Phys. Rev. Lett., 98, 107201, 2007, arXiv:cond-mat/0612486, PDF (279kB)

M. Kriener and M. Braden and D. Senff and O. Zabara and T. Lorenz
Evidence for Multiple Phase Transitions in La1-xCaxCoO3
J. Magn. Magn. Mater., 310, e187, 2007, arXiv:cond-mat/0605721

K. Kordonis and A.V. Sologubenko and T. Lorenz and S.-W. Cheong and A. Freimuth
Spin thermal conductivity of the Haldane chain compound Y2BaNiO5
J. Magn. Magn. Mater., 310, 1245, 2007

S. Stark and O. Heyer and A. Vasiliev and A. Oosawa and H. Tanaka and T. Lorenz
Thermodynamic properties of the field-induced Neel order of TlCuCl3
J. Magn. Magn. Mater., 310, 1374, 2007, arXiv:cond-mat/0610487

C. Ulrich and A. Gössling and M. Grüninger and M. Guennou and H. Roth and M. Cwik and T. Lorenz and G. Khaliullin and B. Keimer
Raman Scattering in the Mott Insulators LaTiO3 and YTiO3: Evidence for Orbital Excitations
Phys. Rev. Lett., 97, 157401, 2006, arXiv.org:cond-mat/0503106, PDF (1261kB)

Maurits W. Haverkort and Zhiwei Hu and Júlio C. Cezar and Tobias Burnus and Helena Hartmann and Marco Reuther and Christian Zobel and Thomas Lorenz and Arata Tanaka and Nicholas B. Brookes and Hui-Huang Hsieh and Hong-Ji Lin and Chien-Te Chen and L. Hao Tjeng
Spin State Transition in LaCoO3 Studied Using Soft X-ray Absorption Spectroscopy and Magnetic Circular Dichroism
Phys. Rev. Lett., 97, 176405, 2006, arXiv.org:cond-mat/0610457, PDF (560kB)

Jan Gegner and Thomas C. Koethe and Hua Wu and Zhiwei Hu and Helena Hartmann and T. Lorenz and T. Fickenscher and R. Pöttgen and L. Hao Tjeng
Electronic structure of RAuMg and RAgMg (R = Eu, Gd, Yb)
Phys. Rev. B, 74, 073102, 2006, arXiv.org:cond-mat/0511511, PDF (516kB)

J. Baier and T. Zabel and M. Kriener and P. Steffens and O. Schumann and O. Friedt and A. Freimuth and A. Revcolevschi and S. Nakatsuji and Y. Maeno and T. Lorenz and M. Braden
Thermodynamic Properties of (Ca,Sr)2RuO4 in Magnetic Fields
Physica B, 378, 497, 2006, arXiv.org:cond-mat/0511220

K. Berggold and T. Lorenz and J. Baier and M. Kriener and D. Senff and S. Barilo and A. Freimuth
Thermal conductivity of R2CuO4, with R = La, Pr and Gd
Physica B, 378, 1064, 2006, arXiv.org:cond-mat/0508154

K. Berggold and T. Lorenz and J. Baier and M. Kriener and D. Senff and H. Roth and A. Severing and H. Hartmann and A. Freimuth and S. Barilo and F. Nakamura
Magnetic heat transport in R2CuO4 (R = La, Pr, Nd, Sm, Eu, and Gd)
Phys. Rev. B, 73, 10, 104430, 2006, arXiv.org:cond-mat/0509414

O. Heyer and N. Hollmann and I. Klassen and S. Jodlauk and L. Bohatý and P. Becker and J.A. Mydosh and T. Lorenz and D.I. Khomskii
A new multiferroic material: MnWO4
J. Phys.: Condens. Matter, 18, L471-L475, 2006

K. Kordonis and A.V. Sologubenko and T. Lorenz and S.-W. Cheong and A. Freimuth
Spin thermal conductivity of the Haldane chain compound Y2BaNiO5
Phys. Rev. Lett., 97, 11, 115901, 2006, arXiv:cond-mat/0603586, PDF (270kB)

N. Johannsen and A. Oosawa and H. Tanaka and A. Vasiliev and T. Lorenz
Uniaxial pressure dependencies of the phase boundary of TlCuCl
Physica B, 378-380, 1043, 2006, arXiv:condmat/0507582

J. Baier and D. Meier and K. Berggold and J. Hemberger and A. Balbashov and J.A. Mydosh and T. Lorenz
Hysteresis effects in the phase diagram of multiferroic GdMnO3
Phys. Rev. B, 73, 10, 100402(R), 2006, arXiv:cond-mat/0601169, PDF (547kB)

K. Berggold and M. Kriener and C. Zobel and A. Reichl and M. Reuther and R. Müller and A. Freimuth and T. Lorenz
Thermal Conductivity, Thermopower, and Figure of Merit of La1-xSrxCoO3
Phys. Rev. B, 72, 155116, 2006, arXiv:cond-mat/0501262

M. Kriener and P. Steffens and J. Baier and O. Schumann and T. Zabel and T. Lorenz and O. Friedt and R. Mueller and A. Gukasov and P. Radaelli and P. Reutler and A. Revcolevschi and S. Nakatsuji and Y. Maeno and M. Braden
Structural aspects of metamagnetism in Ca2-xSrxRuO4 (0.2 < x < 0.5): field tuning of orbital occupation
Phys. Rev. Lett., 95, 26, 267403, 2005, http://link.aps.org/abstract/PRL/v95/e267403, arXiv.org:cond-mat/0408015

R. Rückamp and J. Baier and M. Kriener and M.W. Haverkort and T. Lorenz and G.S. Uhrig and L. Jongen and A. Möller and G. Meyer and M. Grüninger
Zero-field incommensurate spin-Peierls phase with interchain frustration in TiOCl
Phys. Rev. Lett., 95, 097203, 2005, arXiv.org:cond-mat/0503409, PDF (365kB)

R. Rückamp and E. Benckiser and M.W. Haverkort and H. Roth and T. Lorenz and A. Freimuth and L. Jongen and A. Möller and G. Meyer and P. Reutler and B. Büchner and A. Revcolevschi and S.-W. Cheong and C. Sekar and G. Krabbes and M. Grüninger
Optical study of orbital excitations in transition-metal oxides
New J. Phys., 7, 1, 144, 2005, arXiv.org:cond-mat/0503405, PDF (1463kB)

M. W. Haverkort and Z. Hu and A. Tanaka and G. Ghiringehelli and H. Roth and M. Cwik and T. Lorenz and C. Schüßler-Langeheine and S. V. Streltsov and A. S. Mylnikova and V. I. Anisimov and C. de Nadai and N. B. Brookes and H. H. Hsieh and H.-J. Lin and C. T. Chen and T. Mizokawa and Y. Taguchi and Y. Tokura and D. I. Khomskii and L. H. Tjeng
Determination of the Orbital Moment and Crystal-Field Splitting in LaTiO3
Phys. Rev. Lett., 94, 056401, 2005, arXiv.org:cond-mat/0405516, PDF (270kB)

O. Volkova and Yu. Arango and N. Tristan and V. Kataev and E. Gudilin and D. Meier and T. Lorenz and B. Büchner and A. Vasil'ev
Nature of Low-Temperature Phase Transitions in CaMn7O12
JETP Letters, 82, 444, 2005

H. Hartmann and K. Berggold and S. Jodlauk and I. Klassen and K. Kordonis and T. Fickenscher and R. Pöttgen and A. Freimuth and T. Lorenz
Magnetoresistance, specific heat and magnetocaloric effect of equiatomic rare-earth transition-metal magnesium compounds
J. Phys.: Condens. Matter, 17, 7731, 2005, arXiv:cond-mat/0508528

J. Baier and S. Jodlauk and M. Kriener and A. Reichl and C. Zobel and H. Kierspel and A. Freimuth and T. Lorenz
Spin-State Transition and Metal-Insulator Transition in La1-xEuxCoO3
Phys. Rev. B, 71, 014443, 2005, arXiv:cond-mat/0405680

N. Johannsen and A. Vasiliev and A. Oosawa and H. Tanaka and T. Lorenz
Magnetoelastic Coupling in the Spin-Dimer System TlCuCl3
Phys. Rev. Lett., 95, 017205, 2005, arXiv:cond-mat/0412451

M. Braden and O. Friedt and O. Schumann and J. Baier and P. Steffens and M. Kriener and T. Lorenz and F. Bouree and G. Andre and A. Gukasov and P.G. Radaelli and S. Nakastuji and und Y. Maeno
The phase-diagram of Ca2¡xSrxRuO4 : relation between crystal distortions and and physical properties
Mat. Res. Soc. Symp. Proc., 840, 71, 2005

Z. Hu and Hua Wu and M. W. Haverkort and H. H. Hsieh and H. -J. Lin and T. Lorenz and J. Baier and A. Reichl and I. Bonn and C. Felser and A. Tanaka and C. T. Chen and L. H. Tjeng
Different Look at the Spin State of Co3+ Ions in a CoO5 Pyramidal Coordination
Phys. Rev. Lett., 92, 20, 207402, 2004, arXiv.org:cond-mat/0310138, PDF (283kB)

M. Kriener and C. Zobel and A. Reichl and J. Baier and M. Cwik and K. Berggold and H. Kierspel and O. Zabara and A. Freimuth and T. Lorenz
Structure, Magnetization and Resistivity of La1-xMxCoO3 (M = Ca, Sr, and Ba)
Phys. Rev. B, 69, 094417, 2004, arXiv:cond-mat/0401400, PDF (132kB)

R. Lengsdorf and M. Ait-Tahar and S.S. Saxena and M. Ellerby and D.I. Khomskii and H. Micklitz and T. Lorenz and M.M. Abd-Elmeguid
Pressure-induced insulating state in (La,Sr)CoO3
Phys. Rev. B, 69, 140403(R), 2004, arXiv:cond-mat/0504282, PDF (64kB)

M. Markina and K. Klimov and A.N. Vasiliev and A. Freimuth and K. Kordonis and M. Kriener and T. Lorenz and T. Yamauchi and Y. Ueda
Sequence of Phase Transitions in a Quasi-One-Dimensional beta-Na0.33V2O5 Compound with Variable Valence
JETP Letters, 79, 542, 2004, PDF (65kB)

M. Cwik and T. Lorenz and J. Baier and R. Mueller and G. Andre and F. Bouree and F. Lichtenberg and A. Freimuth and E. Mueller-Hartmann and M. Braden
Crystal and magnetic structure of LaTiO3 : evidence for non-degenerate t2g-orbitals
Phys. Rev. B, 68, 6, 060401, 2003, http://link.aps.org/abstract/PRB/v68/e060401, arXiv.org:cond-mat/0302087, PDF (159kB)

M. Hofmann and T. Lorenz and K. Berggold and M. Grüninger and A. Freimuth and G.S. Uhrig and E. Brück
Evidence for a large magnetic heat current in insulating layered cuprates
Phys. Rev. B, 67, 18, 184502, 2003, arXiv:cond-mat/0301093, PDF (64kB)

G. Maris and Y. Ren and V. Volotchaev and C. Zobel and T. Lorenz and T. T. M. Palstra
Evidence for orbital ordering in LaCoO3
Phys. Rev. B, 67, 22, 224423, 2003, PDF (52kB)

M. Markina and A. Vasiliev and J. Müller and M. Lang and K. Kordonis and T. Lorenz and M. Isobe and Y. Ueda
Thermal properties of NaV2O5
J. Magn. Magn. Mater., 258, 398, 2003

M. Grüninger and R. Rückamp and M. Windt and P. Reutler and C. Zobel and T. Lorenz and A. Freimuth and A. Revcolevschi
Experimental Quest for Orbital Waves
Nature (London), 418, 39, 2002

M. Hofmann and T. Lorenz and A. Freimuth and G.S. Uhrig and H. Kageyama and Y. Ueda and G. Dhalenne and A. Revcolevschi
Heat Transport in SrCu2(BO3)2 and CuGeO3
Physica B, 312-313, 597, 2002, arXiv:cond-mat/0108488

C. Zobel and M. Kriener and D. Bruns and J. Baier and M. Grüninger and T. Lorenz and P. Reutler and A. Revcolevschi
Evidence for a low-spin to intermediate-spin state transition in LaCoO3
Phys. Rev. B, 66, 020402(R), 2002, arXiv:cond-mat/0205479, PDF (81kB)

T. Lorenz and M. Hofmann and M. Grüninger and A. Freimuth and G.S. Uhrig and M. Dumm and M. Dressel
Evidence for spin-charge separation in quasi-one-dimensional organic conductors (This article has been retracted!)
Nature (London), 418, 614, 2002, PDF (51kB)

M. Hofmann and T. Lorenz and G.S. Uhrig and H. Kierspel and O. Zabara and A. Freimuth and H. Kageyama and Y. Ueda
Strong Damping of Phononic Heat Current by Magnetic Exitations in SrCu2(BO3)2
Phys. Rev. Lett., 87, 047202, 2001, arXiv:cond-mat/0103012, PDF (243kB)

D. Bruns and B. Büchner and R. Gross and T. Lorenz and S. Uchida
Thermal expansion of La1.85Sr0.15CuO4 in magnetic fields up to 14 Tesla
J. Low Temp. Phys., 117, 1453, 1999

T. Lorenz
Magnetic frustration and spin-Peierls transition in CuGeO3
, , B. Kramer, Advances in Solid State Physics, 39, Vieweg Verlag, Braunschweig, 1999, PDF (1123kB)

B. Büchner and T. Lorenz and R. Walter and H. Kierspel and A. Revcolevschi and G. Dhalenne
Spin-Peierls order parameter and antiferromagnetism in the dimerized and incommensurate phases of Zn-doped CuGeO3
Phys. Rev. B, 59, 6886, 1999, PDF (425kB)

B. Büchner and T. Lorenz and R. Walter and H. Kierspel and A. Revcolevschi and G. Dhalenne
Spin-Peierls order parameter and antiferromagnetism in the dimerized and incommensurate phases of Zn-doped CuGeO3
Phys. Rev. B, 59, 6886, 1999

S. Uma and W. Schnelle and E. Gmelin and G. Rangarajan and S. Skanthakumar and J.W. Lynn and R. Walter and T. Lorenz and B. Büchner and A. Erb
Magnetic Ordering in Single Crystals of PrBa2Cu3O7-d
J. Phys.: Condens. Matter, 10, L33, 1998, PDF (125kB)

T. Lorenz and B. Büchner and P.H.M. van Loosdrecht and F. Schönfeld and G. Chouteau and A. Revcolevschi and G. Dhalenne
Incommensurate phase of CuGeO3: from solitons to sinusoidal modulation
Phys. Rev. Lett., 81, 148, 1998, PDF (222kB)

M. Fischer and P.H.M. van Loosdrecht and G. Güntherodt and B. Büchner and T. Lorenz and M. Breuer and J. Zeman and G. Martinez and G. Dhalenne and A. Revcolevschi
Revival of the spin--Peierls transition in Cu1-xZnxGeO3 under pressure
Phys. Rev. B, 57, 7749, 1998, PDF (128kB)

K. Fabricius and A. Klümper and U. Löw and B. Büchner and T. Lorenz and G. Dhalenne and A. Revcolevschi
Reexamination of the microscopic couplings of the quasi-one-dimensional antiferromagnet CuGeO3
Phys. Rev. B, 57, 1102, 1998, PDF (125kB)

T. Lorenz
Thermodynamische Eigenschaften des Spin-Peierls-Systems CuGeO3
, , PhD thesis, Universität zu Köln, 1998, PDF (2232kB)

U. Köbler and J. Schweizer and P. Chieux and T. Lorenz and B. Büchner and W. Schnelle and F. Deloie and W. Zinn
Evidence for biquadratic exchange interactions in GdAg1-xZnx
J. Magn. Magn. Mater., 170, 110, 1997, PDF (11451kB)

T. Lorenz and H. Kierspel and S. Kleefisch and B. Büchner and E. Gamper and A. Revcolevschi and G. Dhalenne
Specific heat, thermal expansion, and pressure dependencies of the transition temperatures of doped CuGe03
Phys. Rev. B, 56, R501, 1997, PDF (114kB)

T. Lorenz and U. Ammerahl and T. Auweiler and B. Büchner and A. Revcolevschi and G. Dhalenne
Temperature and magnetic-field dependence of the lattice constant in the spin-Peierls cuprate CuGe03 studied by capacitance dilatometry in fields up to 16 T
Phys. Rev. B, 55, 5914, 1997, PDF (315kB)

U. Ammerahl and T. Lorenz and B. Büchner and A. Revcolevschi and G. Dhalenne
Magnetostriction of the spin-Peierls cuprate CuGe03
Z. Phys. B, 102, 71, 1997

U. Ammerahl and T. Lorenz and B. Büchner and A. Revcolevschi and G. Dhalenne
Magnetostriction of the spin-Peierls cuprate CuGe03
Z. Phys. B, 102, 71, 1997, PDF (574kB)

T. Lorenz and U. Ammerahl and R. Ziemes and B. Büchner and A. Revcolevschi and G. Dhalenne
Thermodynamic properties of the incommensurate phase of CuGe03
Phys. Rev. B, 54, R15610, 1996, PDF (96kB)

B. Büchner and U. Ammerahl and T. Lorenz and W. Brenig and G. Dhalenne and and A. Revcolevschi
Magnetic Frustration Induced Formation of the Spin-Peierls Phase in CuGe03: Experimental Evidence
Phys. Rev. Lett., 77, 1624, 1996, PDF (144kB)

Th. Auweiler and T. Lorenz and W. Schlabitz and H. Kierspel and B. Büchner and A. Freimuth and H. Micklitz and I. Tanaka and H. Kojima
Thermal Expansion of a La1.87Sr0.13CuO4 Single Crystal at Tc in High Magnetic Fields
Physica C, 235, 1931, 1994, PDF (248kB)

T. Lorenz
Aufbau eines Magnetkryostaten und Messungen der thermischen Ausdehnung von La1.87Sr0.13CuO4 im transversalen Magnetfeld
, , Diploma thesis, Universität zu Köln, 1994