相关论文: Ultrasoft Fermionic Modes at High Temperature
The Higgs-Top model is studied by a non-perturbative variational extension of the Gaussian Effective Potential that incorporates fermions. In the limit of a very strong Yukawa coupling the one-loop result is shown to follow a…
Fermion bound states in the background of the electroweak SU(2) monopole are investigated for various values of gauge coupling constant $g$, the Higgs self-coupling constant $\lambda$, and the Yukawa coupling constant $y_q$. Numerical…
We discuss fermionic zero modes in the two-dimensional chiral p-wave superconductors. We show quite generally, that without fine-tuning, in a macroscopic sample there is only one or zero of such Majorana-fermion modes depending only on…
Near a quantum-critical point in a metal strong fermion-fermion interaction mediated by a soft collective boson gives rise to incoherent, non-Fermi liquid behavior. It also often gives rise to superconductivity which masks the non-Fermi…
We compute the damping rates of one-particle excitations in a cold ultrarelativistic plasma to leading order in the coupling constant e for three types of interaction: Yukawa coupling to a massless scalar boson, QED and QCD. Damping rates…
We investigate the soft mode at the QCD critical point (CP) on the basis of the functional renormalization group. We calculate the spectral functions in the meson channels in the two-flavor quark--meson model. Our result shows that the…
We present a strong coupling dynamical theory of the superconducting transition in a metal near a QCP towards $Q = 0$ nematic order. We use a fermion-boson model, in which we treat the ratio of effective boson-fermion coupling and the Fermi…
Non-Hermitian multichannel Kondo problems host both non-Fermi liquid and non-Hermitian physics, which provide a prototypical model to explore exotic collective quantum phenomena driven by the two different ingredients. Here, we first…
Heavy fermion materials are compounds in which localized $f$-orbitals hybridize with delocalized $d$ ones, leading to quasiparticles with large renormalized masses. The presence of strongly correlated $f$-electrons at the Fermi level may…
The linear perturbation renormalization group is used to study spinless two-band fermion chains at half-filling. The model consists of two species of spinless fermions, namely localized f and extended p, and it takes into account the…
A momentum space, mean field d-density wave (DDW) Hamiltonian is investigated self-consistently. The pseudo-gapped(PG)state of YBCO is assumed to correspond to the pure DDW state. A relation between thermodynamic potential of the system and…
The Hubbard model is reformulated in terms of different ``colored'' fermion species for the electrons or holes at different lattice sites. Antiferromagnetic ordering or d-wave superconductivity can then be described in terms of…
We study the effective parameters of QED near decoupling temperatures and show that the QED perturbative series is convergent, at temperatures below the decoupling temperature. The renormalization constant of QED acquires different values…
A new phenomenological model is proposed to describe the evolution of the Fermi surface (FS) in a wide range of dopings. It reproduces the key features of the cuprates in the underdoped phase above the superconducting temperature $T_c$. It…
Thermodynamics of the unitary Fermi gas at finite temperature is investigated from the perspective of the expansion over epsilon=4-d with d being the dimensionality of space. We show that the thermodynamics is dominated by bosonic…
We provide evidence that the gauge-fermion interaction in multiflavour quantum electrodynamics in $(2 + 1)$-dimensions is responsible for non-fermi liquid behaviour in the infrared, in the sense of leading to the existence of a non-trivial…
We calculate the collective modes of ultracold trapped alkaline-earth fermionic atoms, which possess an SU($N$) symmetry of the nuclear spin degree of freedom, and a controllable $N$, with $N$ as large as $10$. We calculate the breathing…
We investigated the thermodynamic property of the heavy fermion superconductor UTe$_2$ in pulsed high magnetic fields. The superconducting transition in zero field was observed at $T_{\rm c}$=1.65 K as a sharp heat capacity jump.…
Free nodal fermionic excitations are simple but interesting examples of fermionic quantum criticality in which the dynamic critical exponent $z=1$, and the quasiparticles are well defined. They arise in a number of physical contexts. We…
We analyze the phase diagram of the Yukawa-Sachdev-Ye-Kitaev model, which describes complex fermions randomly interacting with real bosons via a Yukawa coupling, at finite temperatures and varying fermion density. In a recent work [Phys.…