Dr. Theodoulos Costi

Gautam Mitra, Jueting Zheng, Karen Schaefer, Michael Deffner, Jonathan Z. Low, Luis M. Campos, Carmen Herrmann, Theo A. Costi and Elke Scheer
"Singlet-Triplet Kondo Effect in Blatter Radical Molecular Junctions: Zero-Bias Anomalies and Magnetoresistance https://arxiv.org/abs/2408.00366
(submitted)

Spin-Polarized Scanning Tunneling Microscopy Measurements of an Anderson Impurity, Mahasweta Bagchi, Tfyeche Y. Tounsi, Affan Safeer, Camiel van Efferen, Achim Rosch, Thomas Michely, Wouter Jolie, Theo A. Costi and Jeison Fischer, https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.133.246701 https://arxiv.org/abs/2407.14667

Modulated Kondo screening along magnetic mirror twin boundaries in monolayer MoS₂, Camiel van Efferen, Jeison Fischer, Theo A. Costi, Achim Rosch, Thomas Michely and Wouter Jolie, Nature Physics 20, 82-87 (2024), see also Cologne University Press report
"Riddle of Kondo effect solved in ultimately thin wires"
Press report Cologne University (2023)
see also blog post by Camiel van Efferen of behind the scenes making of this story
"Modulated Kondo screening along magnetic mirror twin boundaries in monolayer MoS2"
Physics Community, Springer Nature (2023) see also "Physik in unserer Zeit" article (in German):

"Anderson-Modell korrelierter Elektronen bestätigt", Wouter Jolie, Jeison Fischer, Thomas Michely and Theo Costi,

Treffpunkt Forschung (2024)

Magnetic-Field Universality of the Kondo Effect Revealed by Thermocurrent Spectroscopy,C. Hsu, T. A. Costi, D. Vogel, C. Wegeberg, M. Mayer, H.S.J. van der Zant and P. Gehring, Phys. Rev. Lett. 128 147701 (2022), see also PGI-2 News highlight (2022)
"Detection of the Kondo Effect via Thermocurrent Spectroscopy"
PGI-2 News higlight (2022)

Self-energy method for time-dependent spectral functions of the Anderson impurity model within the time-dependent numerical renormalization group approach,H. T. M. Nghiem and T. A. Costi, Phys. Rev. B 104 205113 (2021)

Time-dependent spectral functions of the Anderson impurity model in response to a quench with application to time-resolved photoemission spectroscopy,H. T. M. Nghiem, H. T. Dang and T. A. Costi, Phys. Rev. B 101 115117 (2020)

Magnetic field dependence of the thermopower of Kondo-correlated quantum dots: Comparison with experiment,T. A. Costi, Phys. Rev. B 100 155126 (2019)

Magnetic field dependence of the thermopower of Kondo-correlated quantum dots, T. A. Costi, Phys. Rev. B 100 161106(R) (2019)

Direct probe of the Seebeck coefficient in a Kondo-correlated single-quantum-dot transistor,B. Dutta, D. Majidi, A. Garcia Corral, P. Erdman, S. Florens, T. A. Costi, H. Courtois, and C. B. Winkelmann, Nano Letters 19 506 (2019), see also PGI-2 News highlight (2019)
"Thermoelectric efficiency of quantum dots now characterizable"
PGI-2 News higlight (2019)

Nonequilibrium thermoelectric transport through vibrating molecular quantum dots, A. Khedri, T. A. Costi and V. Meden, Phys. Rev. B 98 195138 (2018)

Time-dependent numerical renormalization group method for multiple quenches: towards exact results for the long time limit of thermodynamic observables and spectral functions, H. T. M. Nghiem and T. A. Costi, Phys. Rev. B 98 155107 (2018)

Time evolution of the Kondo resonance in response to a quench, H. T. M. Nghiem and T. A. Costi, Phys. Rev. Lett. 119 156601 (2017), see also PGI-2 News highlight (2017)
"Calculating time-dependent spectral functions of correlated impurity systems"
PGI-2 News higlight (2017)

Exponential and power-law renormalization in phonon-assisted tunneling, A. Khedri, T. A. Costi and V. Meden, Phys. Rev. B 96 195155 (2017)

The influence of phonon-assisted tunneling on the linear thermoelectric transport through molecular quantum dots, A. Khedri, V. Meden and T. A. Costi, Phys. Rev. B 96 195156 (2017)

The renormalized superperturbation theory (SPT) approach to the Anderson model in and out of equilibrium, E. Muñoz, F. Zamani, L. Merker, T. A. Costi and S. Kirchner, J. Phys. Conf. Series 807 092001 (2017)

Ohmic two-state system from the perspective of the interacting resonant level model: Thermodynamics and transient dynamics, H. T. M. Nghiem, D. M. Kennes, C. Klöckner, V. Meden, and T. A. Costi, Phys. Rev. B 93 165130 (2016)

Time-Dependent Numerical Renormalization Group Method for Multiple Quenches: Application to General Pulses and Periodic Driving, H. T. M. Nghiem and T. A. Costi, Phys. Rev. B 90 035129 (2014)

Generalization of the Time-Dependent Numerical Renormalization Group Method to Finite Temperatures and General Pulses, H. T. M. Nghiem and T. A. Costi, Phys. Rev. B 89 075118 (2014)

Iron impurities in gold and silver (II): Comparison of transport measurements to numerical renormalization group calculations exploiting non-Abelian symmetries, M. Hanl, A. Weichselbaum, T. A. Costi, F. Mallet, L. Saminadayar, C. Bäuerle, and J. von Delft, Phys. Rev. B 88 075146 (2013)

Conductance scaling in Kondo-correlated quantum dots: role of level asymmetry and charging energy, L. Merker, S. Kirchner, E. Muñoz, T. A. Costi,
Phys. Rev. B 87 165132 (2013) or arXiv:1304.3003

Full density matrix numerical renormalization group calculation of impurity susceptibilitiy and specific heat of the Anderson impurity model, L. Merker, A. Weichselbaum, T. A. Costi, Phys. Rev. B 86 075153 (2012) or arXiv:1207.2631

Numerical renormalization group calculation of impurity internal energy and specific heat of quantum impurity models, L. Merker and T. A. Costi, Phys. Rev. B 86 075150 (2012) or arXiv:1206.3201

Charge Kondo anomalies in PbTe doped with Tl impurities, T. A. Costi and V. Zlatic, Phys. Rev. Lett. 108 036402 (2012) or arXiv:1109.1824, see also "Thermoelectrics: Charge Kondo Effect Improves Efficiency" PGI-2 News higlight (2012)
and for more details "Flipping electron pairs instead of magnetic spins"

Experimental realization of the charge Kondo effect (2012)

Mechanism for large thermoelectric power in molecular quantum dots described by the negative-U Anderson model, S. Andergassen, T. A. Costi and V. Zlatic, Phys. Rev. B 84 241107 (R) (2011) or arXiv:1101.4124, see also PGI-2 News highlight (2012)
"Thermoelectrics: Charge Kondo Effect Improves Efficiency" PGI-2 News higlight (2012)

Spin-1/2 Kondo effect in a InAs nanowire quantum dot: the Unitary limit, conductance scaling and Zeeman splitting, Andrey V. Kretinin, Hadas Shtrikman, David Goldhaber-Gordon, Markus Hanl, Andreas Weichselbaum, Jan von Delft, Theo Costi, Diana Mahalu, Phys. Rev. B 84 245316 (2011) [Editor's suggestion], or arXiv:1108.1773

Thermoelectric effects in correlated quantum dots and molecules, V. Schöps, V. Zlatic and T. A. Costi, J. Phys.: Conf. Ser. 273 012155 (2011) or arXiv:1007.4522

Thermoelectric transport through strongly correlated quantum dots, T. A. Costi and V. Zlatic, Phys. Rev. B 81 235127 (2010) or arXiv:1004.1519

Mechanical control of spin states in spin-1 molecules and the underscreened Kondo effect, J. J. Parks, A. R. Champagne, T. A. Costi, W. W. Shum, A. N. Pasupathy, E. Neuscamman, S. Flores-Torres, P. S. Cornaglia, A. A. Aligia, C. A. Balseiro, G. K.-L. Chan, H. D. Abruña, and D. C. Ralph, Science 328 1370 (2010) or arXiv:1005.0621 , see also "Perspectives" article by P. Jarillo-Herrero
"Pulling Apart Molecular Magnetism"
Science 328 1362 (2010)
see also NSF press release
"Stretching Molecules Yields New Understanding of Electricity"
NSF press release 10-096 (2010)
see also IFF-News highlight
"Mechanical Control of Molecular Spin States"
IFF-News highlight (2010)

Observation of the underscreened Kondo effect in a molecular transistor, N. Roch, S. Florens, T. A. Costi, W. Wernsdorfer and F. Balestro, Phys. Rev. Lett. 103 197202 (2009) or arXiv:0910.1092

Kondo Decoherence: finding the right spin model for iron impurities in gold and silver, T. A. Costi, L. Bergqvist, A. Weichselbaum, J. von Delft, T. Micklitz, A. Rosch, P. Mavropoulos, P. H. Dederichs, F. Mallet, L. Saminadayar, C. Bauerle, Phys. Rev. Lett. 102 056802 (2009) or arXiv:0810.1771
see also the "Viewpoint" article by Piers Coleman:
"Lending an iron hand to spintronics"
Physics 2 6 (2009)
on a related paper by G.-Y. Guo et al.:
"Enhanced Spin Hall Effect by Resonant Skew Scattering in the Orbital-Dependent Kondo Effect"
Spin Hall Effect

Metallic and Insulating Phases of Repulsively Interacting Fermions in a 3D Optical Lattice, U. Schneider, L. Hackermueller, S. Will, Th. Best, I. Bloch,
T. A. Costi, R. W. Helmes, D. Rasch and A. Rosch, Science 322 1520 (2008) or arXiv:0809.1464
see also "Perspectives" article by L. Fallani and M. Inguscio
"Controling Cold-Atom Conductivity"
Science 322 1480 (2008)
see also (in German) "Im Brennpunkt" article by S. Wessel
"Ultrakalt vom Metal zum Isolator"
Physik Journal 8 Nr.3 p.20-21 (2009)
see also FZJ Press report
"Investigating New Materials with Ultracold Atoms: Researchers use optical lattices as a construction kit"
Press report (2008)
see also DLF radio interview with Matthias Schulenburg
"Licht statt Materie"
Deutschlandfunk Forschung Aktuell (2008)

Kondo proximity effect: How does a metal penetrate into a Mott insulator ?, R. W. Helmes, T. A. Costi and A. Rosch, Phys. Rev. Lett. 101 066802 (2008) [Editor's suggestion], or arXiv:0805.0566

Numerical renormalization group method for quantum impurity systems, R. Bulla, T. A. Costi and T. Pruschke, Rev. Mod. Phys. 80 395 (2008) or cond-mat/0701105

Mott Transition of Fermionic Atoms in a Three-Dimensional Optical Trap, R. W. Helmes, T. A. Costi and A. Rosch, Phys. Rev. Lett. 100 056403 (2008) or arXiv:0709.1669

Quantum phase transition in the two-band Hubbard model, T. A. Costi and A. Liebsch, Phys. Rev. Lett. 99 236404 (2007) or arXiv:0707.4535

Magnetic Field Dependence of Dephasing Rate due to Diluted Kondo Impurities, T. Micklitz, T. A. Costi and A. Rosch, Phys. Rev. B 75 054406 (2007) or cond-mat/0610304

Scaling of the low temperature dephasing rate in Kondo systems, F. Mallet, J. Ericsson, D. Mailly, S. Unlubayir, D. Reuter, A. Melnikov, A.D. Wieck, T. Micklitz, A. Rosch, T.A. Costi, L. Saminadayar, C. Bauerle, Phys. Rev. Lett. 97 226804 (2006) or cond-mat/0607154

Non-Fermi-liquid phases in the two-band Hubbard model: Finite-temperature exact diagonalization study of Hund's rule coupling, A. Liebsch and T. A. Costi, Eur. Phys. J. B 51 523 (2006) or cond-mat/060354

Universal dephasing rate due to diluted Kondo impurities, T. Micklitz, A. Altland, T. A. Costi and A. Rosch, Phys. Rev. Lett. 96 226601 (2006) or cond-mat/0509583

The Mott transition: Unconventional transport, spectral weight transfers, and critical behaviour, A. Georges, S. Florens and T. A. Costi, Journal de Phys. IV 114 165 (2004) or cond-mat/0311520

Spectral function of the Kondo model in high magnetic fields, A. Rosch, T. A. Costi, J. Paaske, P. Wölfle, Phys. Rev. B 68 014430 (2003) or cond-mat/0301106

Mott transition and Transport Crossovers in the Organic Compound k-(BEDT-TTF)₂Cu[N(CN)₂]Cl, P. Limelette, P. Wzietek, S. Florens, A. Georges, T. A. Costi, C. Pasquier, D. Jerome, C. Meziere and P. Batail, Phys. Rev. Lett. 91 016401 (2003) or cond-mat/0301478

Entanglement between a qubit and the environment in the spin-boson model, T. A. Costi and R. H. McKenzie, Phys. Rev. A 68 034301 (2003) or quant-ph/0302055

Magnetic Correlations and the Anisotropic Kondo Effect in Ce_1-xLa_xAl₃, E. A. Goremychkin, R. Osborn, B. D. Rainford, T. A. Costi, A. P. Murani, C. A. Scott, P. J. C. King, Phys. Rev. Lett. 89 147201 (2002) or cond-mat/0112005

Thermodynamics of the anisotropic two-channel Kondo problem, G. Zarand, T. Costi, A. Jerez and N. Andrei, Phys. Rev. B 65 134416 (2002) or cond-mat/0110204

Low-energy scales and temperature-dependent photoemission of heavy fermions, T. A. Costi and N. Manini, J. Low. Temp. Phys. 126 835 (2002) or cond-mat/0109357

Magnetotransport through a strongly interacting quantum dot, T. A. Costi, Phys. Rev. B 64 241310(R) (2001) or cond-mat/0103517

Finite temperature numerical renormalization group study of the Mott-transition, R. Bulla, T. A. Costi and D. Vollhardt, Phys. Rev. B 64 045103 (2001) or cond-mat/0012329

Kondo effect in a magnetic field and the magnetoresistivity of Kondo alloys, T. A. Costi, Phys. Rev. Lett. 85 1504 (2000) or cond-mat/0004302

Transmission Phase Shift of a Quantum Dot with Kondo Correlations, Ulrich Gerland, Jan von Delft, Theo Costi and Yuval Oreg, Phys. Rev. Lett. 84 3710 (2000) or cond-mat/9909401

Thermodynamics of the dissipative two-state system: a Bethe Ansatz study, T. A. Costi and G. Zarand, Phys. Rev. B 59 12398 (1999) or cond-mat/9904104

Scaling and universality in the anisotropic Kondo model and the dissipative two-state system, T. A. Costi, Phys. Rev. Lett. 80 1038 (1998) or cond-mat/9712040

Renormalization Group Approach to Non-equilibrium Green Functions in Correlated Impurity Systems, T. A. Costi, Phys. Rev. B 55 3003 (1997) or cond-mat/9706097

Unified description of Fermi and non-Fermi liquid behavior in a conserving slave boson approximation for strongly correlated impurity models, J. Kroha, P. Wölfle, T.A. Costi, Phys. Rev. Lett. 79 261 (1997) or cond-mat/9611096

Spectral density of the local CuO model, T. A. Costi, Phys. Rev. B 55 6670 (1997) or cond-mat/9706097

Equilibrium dynamics of the dissipative two-state system, T. A. Costi and C. Kieffer, Phys. Rev. Lett. 76 1683 (1996) or cond-mat/9601107

Spectral Properties of the Anderson Impurity Model, Comparison of Numerical Renormalization Group and Non--Crossing Approximation, T.A. Costi, J. Kroha and P. Wölfle, Phys. Rev. B 53 1850 (1996) or cond-mat/9507008 [Version with some typos fixed]

Numerical Renormalization Group Study of Pseudo-Fermion and Slave-Boson Spectral Functions in the Single Impurity Anderson Model, T. A. Costi, P. Schmitteckert, J. Kroha, P. Wölfle, nctions in the Single Impurity Anderson Model"
Phys. Rev. Lett. 73 1275 (1994) or cond-mat/9404097 [Version with some typos fixed]

Transport Coefficients of the Anderson Model via the Numerical Renormalization Group, T. A. Costi, A. C. Hewson and V. Zlatic, J. Phys.: Condens. Matter 6 2519 (1994) or cond-mat/9310032 [Version with some typos fixed]

The Thermoelectric Power of Concentrated Kondo Systems, V. Zlatic, T. A. Costi, A. C. Hewson and B. R. Coles, Phys. Rev. B 48 16152 (1993)

Transport Coefficients of the Anderson Model, T. A. Costi and A. C. Hewson, J. Phys.: Condens. Matter 5 L361 (1993) or arXiv:1103.2359 or JPCM-Letter 1993 [Version with references corrected]

Resistivity cross-over for the non-degenerate Anderson model, T. A. Costi and A. C. Hewson, Philos. Mag. B 65 1165 (1992)