相关论文: On superconducting instability in non-Fermi liquid…
Recent measurements on extremely-underdoped YBa2Cu3O6+y [Phys. Rev. Lett. 99, 237003 (2007)] have allowed the critical temperature (T_c), superfluid density [rho_0 (T << T_c)] and dc conductivity [sigma_dc (T ~ T_c)] to be determined for a…
We consider two-dimensional Fermi liquids in the vicinity of a quantum transition to a phase with commensurate, antiferromagnetic long-range order. Depending upon the Fermi surface topology, mean-field spin-density-wave theory predicts two…
The optical properties of single crystals of YBa_2Cu_3O_{6+x} have been examined along the c axis above and below the critical temperature (T_c) for a wide range of oxygen dopings. The temperature dependence of the optically-determined…
We study the superconducting instability of a two-dimensional disordered Fermi liquid weakly coupled to the soft fluctuations associated with proximity to an Ising-ferromagnetic quantum critical point. We derive interaction-induced…
We use renormalization group (RG) analysis and dimensional regularization techniques to study potential superconductivity-inducing four-fermion interactions in systems with critical Fermi surfaces of general dimensions ($m$) and…
The solutions of a renormalized BCS equation are studied in three space dimensions in $s$, $p$ and $d$ waves for finite-range separable potentials in the weak to medium coupling region. In the weak-coupling limit, the present BCS model…
We study an exactly-solvable model which shows a zero-temperature transition from a non-Fermi liquid to a Fermi liquid as a function of particle density. The quantum critical point separating these two states is not associated with the…
Understanding the pairing mechanism of unconventional superconductors remains a core challenge in condensed matter physics, particularly the ongoing debate over whether the related effects caused by electron-electron interactions unify…
In BCS superconductors, the superfluid stiffness is virtually constant at low temperature and only slightly affected by the exponentially low density of thermal quasiparticles. Here, we present an experimental and theoretical study on the…
We study the quantum corrections to the Fermi energy of a two-dimensional electron system, showing that it is attracted towards the Van Hove singularity for a certain range of doping levels. The scaling of the Fermi level allows to cure the…
Spectral anomaly for interacting Fermions is characterized by the spectral function $A([k-k_F],\omega)$ satisfying the scaling relation $A(\Lambda^{y_1} [k-k_F],\Lambda^{y_2}\omega)= \Lambda^{y_A}A([k-k_F],\omega)$, where $y_1$, $y_2$, and…
In several superconductors above the superconducting transition temperature Tc, the electrical resistivity is of the form {\rho} =AT^2. We show that there exists an empirical relation between Tc and A when both vary with an external…
Ta$_{2}$S$_{2}$C compound undergoes superconducting transitions at $T_{cl} = 3.60 \pm 0.02$ K and $T_{cu} = 9.0 \pm 0.2$ K. The nature of successive superconducting transitions has been studied from electrical resistivity, linear and…
The superfluidity and pairing phenomena in ultracold atomic Fermi gases have been of great interest in recent years, with multiple tunable parameters. Here we study the BCS-BEC crossover behavior of balanced two-component Fermi gases in a…
We study color superconductivity with $N_f=1,2,$ and 3 massless flavors of quarks. We present a general formalism to derive and solve the gap equations for condensation in the even-parity channel. This formalism shows that the leading-order…
Scaling relations between the superconducting transition temperature $T_{\rm c}$, the superfluid stiffness $\rho_{\rm s}$ and the normal state conductivity $\sigma_0(T_{\rm c})$ are identified within the class of molecular superconductors.…
Superconductivity at low temperature -- observed in lithium and bismuth, as well as in various low-density superconductors -- calls for developing reliable theoretical and experimental tools for predicting ultralow critical temperatures,…
The solutions of a renormalized BCS model are studied in two space dimensions in $s$, $p$ and $d$ waves for finite-range separable potentials. The gap parameter, the critical temperature $T_c$, the coherence length $\xi$ and the jump in…
Based on renormalization group arguments we establish that for a superconductor in the presence of a weak external magnetic field, $B$, the dependence on $B$ and the deviation from the critical temperature, $\tau$, of a thermodynamic…
In their article, Zhang et al. [Phys. Rev. B 86, 024516 (2012)] present a remarkable result for A$_x$(S)$_y$TiNCl compounds ($\alpha$-phase TiNCl partially intercalated with alkali A and optionally co-intercalated molecular species S),…