Unconventional Superconductivity

The microscopic description of novel superconductivity states in complex materials such as layered copper oxides and iron pnictides is one of the most important challenges in current solid-state physics. Our group uses high-quality single crystals and state-of-the-art experimental methods to derive accurate spectra of spin and charge excitations in these materials. Such data are essential to motivate and test new theoretical concepts for the correlated electron systems that support unconventional superconductivity.

<p>YBa2Cu3O7 crystal array for neutron scattering</p>

YBa2Cu3O7 crystal array for neutron scattering

Recent focus and key Publications


High Temperature Superconductivity in the Cuprates

B. Keimer, S. A. Kivelson, M. R. Norman, S. Uchida, J. Zaanen.
arxiv.org 1409.4673

Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa2Cu3O6.5

R. Mankowsky, A. Subedi, M. Först, S. O. Mariager, M. Chollet, H. T. Lemke, J. S. Robinson, J. M. Glownia, M. P. Minitti, A. Frano, M. Fechner, N. A. Spaldin, T. Loew, B. Keimer, A. Georges & A. Cavalleri.

Optically enhanced coherent transport in YBa2Cu3O6.5 by ultrafast redistribution of interlayer coupling

W. Hu, S. Kaiser, D. Nicoletti, C. R. Hunt, I. Gierz, M. C. Hoffmann, M. Le Tacon, T. Loew, B. Keimer & A. Cavalleri

Ubiquitous Interplay Between Charge Ordering and High-Temperature Superconductivity in Cuprates

E. H. da Silva Neto, P. Aynajian, A. Frano, R. Comin, E. Schierle, E. Weschke, A. Gyenis, J. Wen, J. Schneeloch, Z. Xu, S. Ono, G. Gu, M. Le Tacon, A. Yazdani.

Charge Order Driven by Fermi-Arc Instability in Bi2Sr2−xLaxCuO6+δ
R. Comin, A. Frano, M. M. Yee, Y. Yoshida, H. Eisaki, E. Schierle, E. Weschke, R. Sutarto, F. He, A. Soumyanarayanan, Yang He, M. Le Tacon, I. S. Elfimov, Jennifer E. Hoffman, G. A. Sawatzky, B. Keimer, A. Damascelli.

Momentum-Dependent Charge Correlations in Three-phase competition in YBa2Cu3O6+δ Superconductors Probey by Resonant X-Ray Scattering: Evidence for Three Competing Phases
S. Blanco-Canosa, A. Frano, T. Loew, Y. Lu, J. Porras, G. Ghiringhelli, M. Minola, C. Mazzoli, L. Braicovich, E. Schierle, E. Weschke, M. Le Tacon, B. Keimer.
Phys. Rev. Lett. 110 (2013) 187001; published 3 Mai 2013.

Feedback effect on high-energy magnetic fluctuations in the model high-temperature superconductor HgBa2CuO4 + δ observed by electronic Raman scattering
Yuan Li, M. Le Tacon, M. Bakr, D. Terrade, D. Manske, R. Hackl, L. Ji, M. K. Chan, N. Barišić, X. Zhao, M. Greven, B. Keimer.
Phys. Rev. Lett. 108 (2012), 227003; published 31 May 2012.

Distinct Charge Orders in the Planes and Chains of Ortho-III-Ordered YBa2Cu3O6+δ Superconductors Identified by Resonant Elastic X-ray Scattering
A. J. Achkar, R. Sutarto, X. Mao, F. He, A. Frañó, S. Blanco-Canosa, M. Le Tacon, G. Ghiringhelli, L. Braicovich, M. Minola, M. Moretti Sala, C. Mazzoli, R. Liang, D. A. Bonn, W. N. Hardy, B. Keimer, G. A. Sawatzky, and D. G. Hawthorn.
Phys. Rev. Lett. 109 (2012) 167001; published 17 October 2012.

Long-range incommensurate charge fluctuations in (Y,Nd)Ba2Cu3O6+x
G. Ghiringhelli, M. Le Tacon, M. Minola, S. Blanco-Canosa, C. Mazzoli, N. B. Brookes, G. M. De Luca, A. Frañó, D. G. Hawthorn, F. He, T. Loew, M. Moretti Sala, D. C. Peets, M. Salluzzo, E. Schierle, R. Sutarto, G. A. Sawatzky, E. Weschke, B. Keimer, L. Braicovich.
Science 337 (2012), 821−825; published 17 August 2012.

Iron pnictides

Spin-state crossover model for the magnetism of iron pnictides
J. Chaloupka, G. Khaliullin.
Phys. Rev. Lett. 110 (2013) 207205; published 14 May 2013.

Nanoscale layering of antiferromagnetic and superconducting phases in Rb2Fe4Se5
A. Charnukha, A. Cvitkovic, T. Prokscha, D. Pröpper, N. Ocelic, A. Suter, Z. Salman, E. Morenzoni, J. Deisenhofer, V. Tsurkan, A. Loidl, B. Keimer, A. V. Boris.
Phys. Rev. Lett. 109 (2012), 017003; published 5 July 2012.

Reciprocal-space structure and dispersion of the magnetic resonant mode in the superconducting phase of RbxFe2−ySe2 single crystals
G. Friemel, J. T. Park, T. A. Maier, V. Tsurkan, Yuan Li, J. Deisenhofer, H.-A. Krug von Nidda, A. Loidl, A. Ivanov, B. Keimer, D. S. Inosov.
Phys. Rev. B 85 (2012), 140511(R); published 20 April 2012.

Superconductivity-induced optical anomaly in an iron arsenide
A. Charnukha, P. Popovich, Y. Matiks, D. L. Sun, C. T. Lin, A. N. Yaresko, B. Keimer, A. V. Boris.
Nature Communications 2 (2011), 219; published 1 March 2011.

Magnetic resonant mode in the low-energy spin-excitation spectrum of superconducting Rb2Fe4Se5 single crystals
J. T. Park, G. Friemel, Yuan Li, J.-H. Kim, V. Tsurkan, J. Deisenhofer, H.-A. Krug von Nidda, A. Loidl, A. Ivanov, B. Keimer, D. S. Inosov.
Phys. Rev. Lett. 107 (2011), 177005; published 19 October 2011.

Eliashberg approach to infrared anomalies induced by the superconducting state of Ba0.68K0.32Fe2As2 single crystals
A. Charnukha, O. V. Dolgov, A. A. Golubov, Y. Matiks, D. L. Sun, C. T. Lin, B. Keimer, A. V. Boris.
Phys. Rev. B 84 (2011), 174511; published 18 November 2011.

Normal-state spin dynamics and temperature-dependent spin-resonance energy in optimally doped BaFe1.85Co0.15As2
D. S. Inosov, J. T. Park, P. Bourges, D. L. Sun, Y. Sidis, A. Schneidewind, K. Hradil, D. Haug, C. T. Lin, B. Keimer, V. Hinkov.
Nature Physics 6 (2010), 178–181; published 1 March 2010.
Supplementary information