Related papers: Quantum fluctuation driven first order phase trans…
In the vicinity of a phase transition, the order parameter starts fluctuating before vanishing at the critical point. The fluctuation regime, i.e. the way the ordered phase disappears, is a characteristics of a transition, and determines…
One of the greatest challenges to Landau's Fermi liquid theory - the standard theory of metals - is presented by complex materials with strong electronic correlations. In these materials, non-Fermi liquid transport and thermodynamic…
This report is devoted to the building of the theory and analyzing the phenomenon which take place in such strong correlated Fermi systems as High temperature superconductors, metals with heavy fermions and quasi two dimensional…
We present a new perspective on thermal and quantum phase transitions (QPT) in $(2+1)$-dimensional quantum chromodynamics based on symmetries, topology, and quantum dynamical structure of the baryon ground state in the large $N_c$ limit for…
We investigate the interplay of quantum fluctuations and magnetic anisotropies in metallic ferromagnets. Our central result is that fluctuations close to a quantum critical point can drive the moments to point along a magnetic hard axis. As…
The nature of the quantum valence transition is studied in the one-dimensional periodic Anderson model with Coulomb repulsion between f and conduction electrons by the density-matrix renormalization group method. It is found that the…
We investigate thermodynamic phases, including the phase of coexistence of superconductivity and ferromagnetism, the possible phase transitions of first and second order, and the shape of the phase diagram in mean-field approximation for a…
We have shown that the Landau paradigm based upon both the quasiparticle concept and the notion of the order parameter can be used to explain the anomalous behavior of heavy fermion metals. Exploiting this paradigm and the fermion…
The interplay between electron-electron interactions and weak localization (or anti-localization) phenomena in two-dimensional systems can significantly enhance the superconducting transition temperature. We develop the theory of quantum…
In one dimensional wires, fluctuations destroy superconducting long-range order and stiffness at finite temperatures; in an infinite wire, quasi-long range order and stiffness survive at zero temperature if the wire's dimensionless…
The magnon exchange mechanism of superconductivity was developed to explain in a natural way the fact that the superconductivity in $UGe_2$, $ZrZn_2$ and $URhGe$ is confined to the ferromagnetic phase.The order parameter is a spin…
We report on the itinerant ferromagnetic superconductor UGe_2 through ^73Ge-NQR measurements under pressure (P). The P dependence of the NQR spectrum signals a first-order transition from the low-temperature (T) and low-P ferromagnetic…
The temperature-pressure phase diagram of ferromagnetic superconductor UCoGe includes four phase transitions. They are between the paramagnetic and the ferromagnetic states with the subsequent transition in the superconducting ferromagnetic…
Multi-orbital Hubbard models are shown to exhibit a spatially isotropic spin-triplet superconducting phase, where equal-spin electrons in different local orbitals are paired. This superconducting state is stabilized in the spin-freezing…
The origin of the strange metallic behavior observed in a wide range of quantum materials is an open challenge to condensed matter physics. Historically, strange metals were uniquely associated with antiferromagnetic quantum critical points…
We study the renormalization of the quasiparticle properties in weak ferromagnetic metals, due to spin fluctuations, away from the quantum critical point for small magnetic moment. We explain the origin of the s-wave superconducting…
The possibility of a zero temperature, altermagnetic instability in anisotropic two dimensional electron systems in the diffusive regime is analyzed, in the presence and absence of spin-orbit coupling. Allowing for ferromagnetism, a phase…
Pd in U(Pt_{1-x}Pd_x)_3 suppresses the superconducting T_c to 0 K at critical concentration x_c of 0.007 and induces a conventional AFM state for x > x_c. The resistivity below 1 K shows a deviation from Fermi liquid behavior described by a…
We clarify that metamagnetic transitions in three dimensions show unusual properties as quantum phase transitions if they are accompanied by changes in Fermi-surface topology. An unconventional universality deeply affected by the…
The zero temperature, or quantum, metal-superconductor phase transition is studied in disordered systems in dimension greater than two. A effective local field theory is developed that keeps all soft modes or fluctuations explicitly. A…