Related papers: A controlled expansion for certain non-Fermi liqui…
The complete lack of theoretical understanding of the quantum critical states found in the heavy fermion metals and the normal states of the high-T$_c$ superconductors is routed in deep fundamental problem of condensed matter physics: the…
We study the fermion-boson coupled system in $d=3-\epsilon$ space dimensions near the quantum phase transition; infinite many boson modes located on a sphere become critical simultaneously, which is dubbed "critical boson sphere" (CBS). The…
At the nematic quantum critical point that exists in the $d_{x^2-y^2}$-wave superconducting dome of cuprates, the massless nodal fermions interact strongly with the quantum critical fluctuation of nematic order. We study this problem by…
We consider the planar local patch approximation of $d=2$ fermions at finite density coupled to a critical boson. In the quenched or Bloch-Nordsieck approximation, where one takes the limit of fermion flavors $N_f\rightarrow 0$, the fermion…
We calculate analytically the low temperature quasi-particle scattering rate, the conductivity, and the specific heat in weakly disordered metals close to a quantum critical point, via the use of a proper fluctuation potential $V(q,\omega)$…
A new bosonic, excitonic method for interacting electrons is developed. For two-dimensional electron liquid, it reveals a noncompensated quantum crystal phase ranging from the high density, or vanishing Coulomb interaction, limit: $r_s=0$,…
We study the electronic spectral function of a metal in the vicinity of an antiferromagnetic (AFM) quantum critical point, focusing on a situation where the bare bandwidth of the spin fluctuations is significantly smaller than the Fermi…
We review a recently developed method, based on an exact auxiliary boson representation, to describe both Fermi liquid and non-Fermi liquid behavior in quantum impurity systems. Coherent spin and charge fluctuation processes are taken into…
We present a formalism for strongly correlated systems with fermions coupled to bosonic modes. We construct the three-particle irreducible functional $\mathcal{K}$ by successive Legendre transformations of the free energy of the system. We…
We study the influence of quantum fluctuations on the electron self energy in the normal state of iron-pnictide superconductors using a five orbital tight binding model with generalized Hubbard on-site interactions. Within a one-loop…
(1) The temperature dependence of the specific heat for a marginal Fermi liquid has been calculated. (2) We calculated the self-energy at T=0 for a two dimensional fermionic system with hyperbolic dispersion. The existence of the saddle…
Quantum critical systems derive their finite temperature properties from the influence of a zero temperature quantum phase transition. The paradigm is essential for understanding unconventional high-Tc superconductors and the non-Fermi…
We study the problem of the damping of collective modes close to a Pomeranchuk quantum critical point in a Fermi liquid. In analogy with problems in dissipative open quantum systems, we derive the Landau damping of a Fermi liquid by…
We review the intriguing many-body physics resulting out of the interplay of a single, local impurity and the two-particle interaction in a one-dimensional Fermi system. Even if the underlying homogeneous correlated system is taken to be…
We revisit the interplay between superconductivity and quantum criticality when thermal effects from virtual static bosons are included. These contributions, which arise from an effective theory compactified on the thermal circle, strongly…
I review our incomplete understanding of non-Fermi liquid behavior in heavy fermion systems at a quantum critical point. General considerations suggest that critical antiferromagnetic fluctuations do not destroy the Fermi surface by…
We derive multidimensional bosonization directly from the electron gas in a low-energy, low momentum regime where $\omega\gg \frac{k^2}{k_F}$, such that the dispersion can be linearized. To reach this limit, the Fermi momentum and the…
Non-Fermi liquid phenomena arise naturally near critical points of Landau ordering transitions in metallic systems, where strong fluctuations of a bosonic order parameter destroy coherent quasiparticles. Despite progress in developing…
We study the problem of disorder-free metals near a continuous quantum critical point. We depart from the standard paradigm of Hertz and Millis, and treat both fermions and bosons i.e. order parameter fields) on equal footing. We construct…
We analyze quantum criticality at finite temperature for a class of non-Fermi liquids with massless bosons. Finite temperature gives rise to new infrared singularities that invalidate standard perturbative treatments. We show how such…