Related papers: Enhanced Superconductivity at a Corner for the Lin…
A study of temperature dependences of the upper critical field B_{c2}(T) and surface impedance Z(T)=R(T)+iX(T) in Ba_{1-x}K_xBiO_3 single crystals that have transition temperatures in the range 6 < T_c < 32 K (roughly 0.6>x>0.4) reveals a…
We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a…
The symmetry of the superconducting order parameter, or simply the ``gap'', provides certain constraints on the actual mechanism that gives rise to pairing and ultimately to superconductivity. In this work we show how superconducting phases…
We explore the temperature effects in the superconducting phases of a hybridized two-band system. We show that for zero hybridization between the bands, there are two different critical temperatures. However, for any finite hybridization…
Superconducting transitions are driven by thermal fluctuations close to the transition temperature, Tc. These fluctuations are averaged out in global measurements, leaving imprints on susceptibility and resistance measurements. Here, we use…
We studied the partial substitution of Ag in the noncentrosymetric superconducting compounds Li$_2$Pd$_{3-x}$Ag$_x$B with x=0.0, 0.1 and 0.3. Magnetization, resistivity and specific heat measurements were performed in this system. From…
We calculate the critical temperature below which an excitonic insulator exists at the pressure-induced semiconductor-semimetal transition. Our approach is based on an effective-mass model for valence and conduction band electrons…
Thin superconducting films form a unique platform for geometrically-confined, strongly-interacting electrons. They allow an inherent competition between disorder and superconductivity, which in turn enables the intriguing…
Boundary conditions for unconventional superconducting order parameter are obtained on the basis of a microscopic theory. The upper critical field in a superconducting film is examined for unconventional superconductors with two-component…
The thermodynamic critical field $B_{\rm c}$ provides direct access to the superconducting condensation energy, yet its pressure dependence has been studied much less extensively than that of the transition temperature. Here,…
Cold fermionic atoms are known to enter the universal strongly coupled regime as their scattering length $a$ gets large compared to the inter-particle distances. Recent experimental data provide important critical parameters of such system.…
We show theoretically that a superconducting critical temperature can be effectively increased in a high-entropy mixture of electrons belonging to conduction and valence bands. In order to employ the entropy of mixing into the…
Despite more than two decades of intensive investigations, the true nature of high temperature (high-$T_c$) superconductivity observed in the cuprates remains elusive to the researchers. In particular, in the so-called `underdoped' region,…
We investigate superconducting systems with the use of the phenomenological Landau's theory of second order phase transitions, including into the considerations the critical behaviour of the chemical potential. We derive in this way a…
In the paper, the thermodynamic properties of the CaLi$_2$ superconductor have been studied. It has been assumed the high value of the pressure: $p=100$ GPa. The thermodynamic critical field ($H_{C}$) and the specific heats for the…
Departing from the assumption that pairing is induced by an retarded external 'bosonic glue', we reformulate the Bardeen-Cooper-Schrieffer theory of superconductivity as a scaling theory. Conventional superconductors correspond with the…
The paraconductivity, originating from critical superconducting order-parameter fluctuations in the vicinity of the critical temperature in a layered superconductor is calculated in the frame of the self-consistent Hartree approximation,…
A stability criterion is worked out for the superconducting phase. The validity of a prerequisite, established previously for persistent currents, is thereby confirmed. Temperature dependence is given for the specific heat and concentration…
We investigate the impact of two-level systems (TLSs) on superconductivity, treating them as soft modes localised in real space. We show that these defects can either enhance or suppress the superconducting critical temperature, depending…
We present temperature dependences of the large and the small superconducting gaps measured directly by SnS-Andreev spectroscopy in various Fe-based superconductors and MgB$_2$. The experimental $\Delta_{L,S}(T)$ are well-fitted with a…