59 citations · 625 across the 32 of their papers we have counts for
7 papers · 1 filter
Vortex phases and glassy dynamics in the highly anisotropic superconductor HgBaCuO
Serena Eley, Roland Willa, Mun K. Chan +2
We present an extensive study of vortex dynamics in a high-quality single crystal of HgBaCuO (Hg1201), a highly anisotropic superconductor that is a model system for st…
Melting of vortex lattice in magnetic superconductor
A. E. Koshelev, K. Willa, R. Willa +6
The iron-based superconductors are characterized by strong fluctuations due to high transition temperatures and small coherence lengths. We investigate fluctuation behavior in the…
Thermal creep emerging from cooling a tilted vortex lattice in uniaxial superconductor
Roland Willa, Jose Augusto Galvis, Jose Benito-Llorens +3
A perturbed system relaxes towards an equilibrium given by a minimum in the potential energy landscape. This often occurs by thermally activated jumps over metastable states. The c…
Phase transition preceding magnetic long-range order in the double perovskite Ba2NaOsO6
Kristin Willa, Roland Willa, Ulrich Welp +4
Recent theoretical studies [Chen et al., Phys. Rev. B 82, 174440 (2010), Ishizuka et al., Phys. Rev. B 90, 184422 (2014)] for the magnetic Mott insulator Ba2NaOsO6 have proposed a…
Anisotropic upper critical field of pristine and proton-irradiated single crystals of the magnetically ordered superconductor RbEuFeAs
M. P. Smylie, A. E. Koshelev, K. Willa +12
We present a study of the upper critical field, H, of pristine and proton-irradiated RbEuFeAs crystals in pulsed magnetic fields of up to 65 T. The data for H…
Strain tuning and anisotropic spin correlations in iron-based systems
Roland Willa, Max Fritz, Jörg Schmalian
Nematic order in the iron-based superconductors is closely tied to a lattice distortion and a structural transition from tetragonal to orthorhombic symmetry. External stress of the…
Strong pinning theory of thermal vortex creep in type II superconductors
Martin Buchacek, Vadim B. Geshkenbein, Roland Willa +1
We study thermal effects on pinning and creep in type-II superconductors where vortices interact with a low density of strong point-like defects with pinning energy and…