Torsional strain in Weyl semimetals excites a unidirectional chiral density wave propagating in the direction of the torsional vector. This gapless excitation, named the chiral sound wave, is generated by a particular realization of the axial anomaly via the triple-axial (AAA) anomalous diagram. We show that the presence of the torsion-generated chiral sound leads to a linear behavior of the...
We review recent studies of the Casimir effect in non-perturbative regimes within the lattice gauge field theory. The Casimir effect is a quantum phenomenon rooted in the fact that quantum fields' vacuum fluctuations are affected by physical objects and boundaries. As the energy spectrum of vacuum fluctuations depends on distances between (and geometries of) physical bodies, the quantum vacuum...
We disscuss Chiral Separation Effect in case of fermions with spin-3/2. We discuss two types of fermions - relativistic Rarita-Schwinger fermions and quasispin 3/2 fermions in semimetals. In all cases coefficients in the conductivity of the chiral separation effect and in the axial anomaly coincide
We discuss chiral separation effect in the systems with spatial non - homogeneity. It may be caused by non - uniform electric potential or by another reasons, which do not, however, break chiral symmetry of an effective low energy theory. Such low energy effective theory describes quasiparticles close to the Fermi surfaces. In the presence of constant external magnetic field the non -...
The quantum Hall conductivity in the presence of constant magnetic field may be represented as the topological TKNN invariant. Recently the generalization of this expression has been proposed for the non - uniform magnetic field. The quantum Hall conductivity is represented as the topological invariant in phase space in terms of the Wigner transformed two - point Green function. This...
Abstract:
We study the effect of anisotropy on dynamical gap generation in graphene. We work with a low energy effective theory obtained from a tight-binding Hamiltonian expanded around the Dirac points in momentum space. The resulting continuum quantum field theory is called reduced quantum electrodynamics (RQED 3+1). The theory is strongly coupled, and we use a non-perturbative...
We report results from an extensive study of the Lefschetz thimbles decomposition for the Hubbard model on the hexagonal and square lattices. This study, which employs continuous auxiliary fields and the gradient flow with exact evaluation of fermionic determinant, allowed us to construct the complete Lefschetz thimbles decomposition of the model. We found all important saddle points of the...
A new version of exact Wigner-Weyl calculus for tight-binding lattice models is proposed and discussed in detail. It allows to express various physical quantities through Weyl symbols of Green’s functions. Hall conductivity this way is represented using the proposed formalism as a topological invariant including the non-homogenous systems.
We study the dependence of the electric conductivity on chemical potential in finite-density SU(2) gauge theory with Nf=2 flavours of rooted staggered sea quarks, in combination with Wilson-Dirac and Domain Wall valence quarks. The pion mass is reasonably small with mπ/mρ≈0.4. We concentrate in particular on the vicinity of the chiral crossover, where we find the low-frequency electric...