132 citations · 542 across the 29 of their papers we have counts for
14 papers · 1 filter
Absence of hexagonal to square structural transition in LiFeAs vortex matter
Sven Hoffmann, Ronny Schlegel, Christian Salazar +9
We investigated magnetic vortices in two stoichiometric LiFeAs samples by means of scanning tunneling microscopy and spectroscopy. The vortices were revealed by measuring the local…
Elastoresistivity of heavily hole doped 122 iron pnictides superconductors
Xiaochen Hong, Steffen Sykora, Federico Caglieris +8
Nematicity in the heavily hole-doped iron pnictide superconductors remains controversial. Sizeable nematic fluctuations and even nematic orders far from a magnetic instability were…
Ubiquitous enhancement of nematic fluctuations across the phase diagram of iron based superconductors probed by the Nernst effect
Christoph Wuttke, Federico Caglieris, Steffen Sykora +11
The role of nematic fluctuations for unconventional superconductivity has been subject of intense discussions for many years. In iron-based superconductors, the most established pr…
Renormalization approach to the superconducting Kondo model
Steffen Sykora, Tobias Meng
An approach to bound states based on unitary transformations of Hamiltonians is presented. The method is applied to study the interaction between electrons in a BCS -wave superc…
Strain-derivative of thermoelectric properties: a sensitive probe for nematicity
Federico Caglieris, Christoph Wuttke, Xiaochen Hong +6
The nematic instability of iron-based superconductors is an undebatable ingredient of the physics of iron-based superconductors. Yet, its origin remains enigmatic as it involves a…
Theoretical approach to resonant inelastic x-ray scattering in iron-based superconductors at the energy scale of the superconducting gap
Pasquale Marra, Jeroen van den Brink, Steffen Sykora
We develop a phenomenological theory to predict the characteristic features of the momentum-dependent scattering amplitude in resonant inelastic x-ray scattering (RIXS) at the ener…
Interband Quasiparticle Scattering in Superconducting LiFeAs Reconciles Photoemission and Tunneling Measurements
Christian Hess, Steffen Sykora, Torben Hänke +7
Several angle resolved photoemission spectroscopy (ARPES) studies reveal a poorly nested Fermi surface of LiFeAs, far away from a spin density wave instability, and clear-cut super…
Resonant Inelastic X-Ray Scattering as a Probe of the Phase and Excitations of the Order Parameter of Superconductors
Pasquale Marra, Steffen Sykora, Krzysztof Wohlfeld +1
The capability to probe the dispersion of elementary spin, charge, orbital, and lattice excitations has positioned resonant inelastic x-ray scattering (RIXS) at the forefront of ph…
Incommensurate magnetic fluctuations and Fermi surface topology in LiFeAs
J. Knolle, V. B. Zabolotnyy, I. Eremin +12
Using the angle-resolved photoemission spectroscopy (ARPES) data accumulated over the whole Brillouin zone (BZ) in LiFeAs we analyze the itinerant component of the dynamic spin sus…
Probing the Unconventional Superconducting State of LiFeAs by Quasiparticle Interference
T. Hänke, S. Sykora, R. Schlegel +7
A crucial step in revealing the nature of unconventional superconductivity is to investigate the symmetry of the superconducting order parameter. Scanning tunneling spectroscopy ha…
Quasiparticle interference in an iron-based superconductor
Steffen Sykora, Piers Coleman
We develop a model for the effect of a magnetic field on quasiparticle interference in an iron-based superconductor. Recently, scanning tunneling experiments have been performed on…
Microscopic approach to high-temperature superconductors: Superconducting phase
S. Sykora, K. W. Becker
Despite the intense theoretical and experimental effort, an understanding of the superconducting pairing mechanism of the high-temperature superconductors, leading to an unpreceden…
Microscopic approach to high-temperature superconductors: Pseudogap phase
S. Sykora, K. W. Becker
Despite the intense theoretical and experimental effort, an understanding of the superconducting pairing mechanism of the high-temperature superconductors is still lacking. An addi…
Coexistence of superconductivity and charge-density waves in a two-dimensional Holstein model at half-filling
S. Sykora, A. Hübsch, K. W. Becker
In one dimension the coupling of electrons to phonons leads to a transition from a metallic to a Peierls distorted insulated state if the coupling exceeds a critical value. On the…