Related papers: Low temperature vortex liquid in $\rm La_{2-x}Sr_x…
The spontaneous expulsion of applied magnetic field, the Meissner effect, is a defining feature of superconductors; in Type-II superconductors above the lower critical field, this screening takes the form of a lattice of magnetic flux…
We study the effects of weak columnar and point disorder on the vortex-lattice phase transitions in high temperature superconductors. The combined effect of thermal fluctuations and of quenched disorder is investigated using a simplified…
It is suggested that the center vortex confinement mechanism, familiar in hadronic physics, may have some relevance to high-T$_\text{c}$ phenomena. We focus specifically on the transition from the superconducting phase to the pseudogap…
We study the problem of phase coherence in doped striped cuprates. We assume the stripes to form a network of one-dimensional Luttinger liquids which are dominated by superconducting fluctuations and pinned by impurities. The problem of…
A central issue in the physics of high temperature superconductors is to understand superconductivity within a single copper-oxide layer or bilayer, the fundamental structural unit in the cuprates, and how it is lost with underdoping. As…
We discuss the zero field superconducting phase transition in a finite system of magnetically coupled superconducting layers. Transverse screening is modified by the presence of other layers resulting in topological excitations with…
We study the spin fluctuations of pure and Zn-substituted high temperature superconductors (HTS) using the muon spin relaxation (muSR) technique. Superconductivity is found to coexist with low frequency spin fluctuations over a large region…
We study the phase diagram of the superconducting vortex system in layered high-temperature superconductors in the presence of a magnetic field perpendicular to the layers and of random atomic scale point pinning centers. We consider the…
Measurements of magneto-resistivity and magnetic susceptibility were performed on single crystals of superconducting Ba(Fe$_{0.9}$Co$_{0.1}$)$_{2}$As$_{2}$ close to the conditions of optimal doping. The high quality of the investigated…
We report on a small angle neutron scattering study of the vortex lattice in overdoped La{2-x}Sr{x}CuO{4} (x=0.2) up to high magnetic fields (9.5 Tesla) applied perpendicular to the CuO2 planes. At low magnetic fields we observe a crossover…
Due to their proximity to an antiferromagnetic phase and to the mysterious pseudogap, underdoped cuprates have attracted great interest in the high Tc community for many years. A central issue concerns the role of quantum and thermal…
Single crystals of the layered organic type II superconductor, $\kappa$-(BEDT-TTF)$_{2}$Cu(NCS)$_{2}$, have been studied in magnetic fields of up to 33 T and at temperatures between 0.5 K and 11 K using a compact differential susceptometer.…
The hexatic fluid refers to a phase in between a solid and a liquid which has short range positional order but quasi-long range orientational order. In the celebrated theory of Berezinskii, Kosterlitz and Thouless and subsequently refined…
Precision measurements of the vortex phase diagram in single crystals of the layered superconductor Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ in oblique magnetic fields confirm the existence of a second phase transition, in addition to the…
We present a systematic study of the topology of the vortex solid phase in superconducting Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ samples with low doses of columnar defects. A new state of vortex matter imposed by the presence of geometrical…
We propose a new magnetic phase diagram of La2-xSrxCuO4 around a quantum critical point x = 1/9 based on field-cooled magnetization measurements and critical fittings. A new phase boundary Tm2(H) is discovered which buries deeply below the…
In underdoped cuprates the normal state is highly anomalous and is characterized as a pseudogap phase. The question of how to describe the ``normal'' core of a superconducting vortex is an outstanding open problem. We show that the SU(2)…
We report the analysis of the magnetic fluctuations in the superconducing La_{2-x}Sr_xCuO_4 and the related lanthanum cuprates having the different symmetry of the low temperature structure. The NMR and ESR investigations revealed the…
A theory of strongly correlated electron or hole liquids with the fermion condensate is presented and applied to the consideration of quasiparticle excitations in high temperature superconductors, in their superconducting and normal states.…
Vortices in superconductors can help identify emergent phenomena but certain fundamental aspects of vortices, such as their entropy, remain poorly understood. Here, we study the vortex entropy in underdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ by…