Related papers: Quantum critical point in high-temperature superco…
According to Landau criterion, a phase transition should be first order when cubic terms of order parameters are allowed in its effective Ginzburg-Landau free energy. Recently, it was shown by renormalization group (RG) analysis that…
We present magnetoresistivity measurements on the heavy-fermion superconductor UTe$_{2}$ in pulsed magnetic fields $\mu_0H$ up to 68~T and temperatures $T$ from 1.4 to 80~K. Magnetic fields applied along the three crystallographic…
To achieve room-temperature superconductivity, a mechanism is needed that provides heavy quasiparticles at room temperature. In heavy fermion systems such localization is prototypically present only at liquid helium temperatures. In these…
When a 2D superconductor is subjected to a strong in-plane magnetic field, Zeeman polarization of the Fermi surface can give rise to inhomogeneous FFLO order with a spatially modulated gap. Further increase of the magnetic field eventually…
Quantum criticality due to the valence transition in some Yb-based heavy fermion metals has gradually turned out to play a crucial role to understand the non-Fermi liquid properties that cannot be understood from the conventional quantum…
We grew single crystals of the recently discovered heavy fermion superconductor UTe2, and measured the resistivity, specific heat and magnetoresistance. Superconductivity (SC) was clearly detected at Tsc=1.65K as sharp drop of the…
We report low-temperature calorimetric, magnetic and resistivity measurements on the antiferromagnetic (AF) heavy-fermion metal YbRh$_2$Si$_2$ (${T_N =}$ 70 mK) as a function of magnetic field $B$. While for fields exceeding the critical…
The strange metal phases found to develop in a wide range of materials near a quantum critical point (QCP), have posed a long-standing mystery. The frequent association of strange metals with unconventional superconductivity and…
Spin fluctuations (SF) and SF-mediated superconductivity (SC) in quasi-two-dimensional metals around the antiferrromagnetic (AF) quantum critical point (QCP) are investigated by using the self-consistent renormalization theory for SF and…
Metals typically have multiple Fermi surface sheets, and when they enter the superconducting state, some electrons on these sheets may remain uncondensed, or their superconducting pairs can be rapidly destroyed by a magnetic field.…
We describe the approach of the superconducting state as a sequence of cross-over phenomena. As the temperature is decreased, uncorrelated pairing of the electrons leads to the opening of a pseudogap at T_F^*. Upon further lowering the…
We present thermoelectric power and resistivity measurements in the ferromagnetic superconductor URhGe for magnetic field applied along the hard magnetization b axis of the orthorhombic crystal. Reentrant superconductivity is observed near…
Quantum phase transitions in metals are often accompanied by violations of Fermi liquid behavior in the quantum critical regime. Particularly fascinating are transitions beyond the Landau-Ginzburg-Wilson concept of a local order parameter.…
Recent advances in ultrafast measurement in cold atoms, as well as pump-probe spectroscopy of $K_3 C_{60}$ films, have opened the possibility of rapidly quenching systems of interacting fermions to, and across, a finite temperature…
We report measurements of the pressure-dependent superconducting transition temperature $T_c$ and electrical resistivity of the heavy-fermion compound CeCoIn$_5$. Pressure moves CeCoIn$_5$ away from its proximity to a quantum-critical point…
High-$T_c$ superconductivity is unconventional because the gap is not isotropic as in simple metals but has $d_{x^2-y^2}$ symmetry with lines of nodes. In a fascinating thermal transport experiment on a high-$T_c$ superconductor, Krishana…
We report measurements of in-plane electrical and thermal transport properties in the limit $T \rightarrow 0$ near the unconventional quantum critical point in the heavy-fermion metal $\beta$-YbAlB$_4$. The high Kondo temperature $T_K$…
The phase diagram of the heavy fermion compound UTe$_2$ contains multiple superconducting phases, several of which show characteristics of odd-parity pairing. We have investigated the pressure dependence of the superconducting transition in…
We consider two-dimensional Fermi systems with quadratic band touching and $C_3$ symmetry, as realizable in Bernal-stacked honeycomb bilayers. Within a renormalization-group analysis, we demonstrate the existence of a quantum critical point…
The effect of a quantum phase transition associated with the appearance of the fermion condensate in an electron liquid on the properties of superconductors is considered. It is shown that the electron system in both superconducting and…