Single-photon sources are essential building blocks in quantum photonic networks, where quantum-mechanical properties of photons are utilised to achieve quantum technologies such as quantum cryptography and quantum computing. Most conventional solid-state single-photon sources are based on single emitters such as self-assembled quantum dots, which ...
We devise a theory of adsorption of low-energy atoms on suspended graphene membranes maintained at 10 K based on a model of atom-acoustic phonon interactions. Our primary technique includes a non-perturbative method which treats the dynamics of the multiple phonons in an exact manner within the purview of the Independent Boson Model. We present a s...
In a quantum Hall system, the finite-wavevector Hall conductivity displays an intriguing dependence on the Hall viscosity, a coefficient that describes the non-dissipative response of the fluid to a velocity gradient. In this paper, we pursue this connection in detail for quantum Hall systems on a lattice, noting that the neat continuum relation br...
Disorder such as impurities and dislocations in Weyl semimetals (SMs) drives a quantum critical point (QCP) where the density of states at the Weyl point gains a non-zero value. Near the QCP, the asymptotic low energy singularities of physical quantities are controlled by the critical exponents $\nu$ and $z$. The nuclear spin-lattice relaxation rat...
Many magnetic point-group symmetries induce a topological classification on crystalline insulators, dividing them into those that have a nonzero quantized Chern-Simons magnetoelectric coupling ("axion-odd" or "topological"), and those that do not ("axion-even" or "trivial"). For time-reversal or inversion symmetries, the resulting topological state...
We study the spin transport through a 1D quantum Ising$\mid$XY$\mid$Ising spin link that emulates a topological superconducting$\mid$normal$\mid$superconducting structure via Jordan-Wigner (JW) transformation. We calculate, both analytically and numerically, the spectrum of spin Andreev bound states and the resulting $\mathbb{Z}_2$ fractional spin ...
We analyze the evidence of Majorana zero modes in nanowires that came from tunneling spectroscopy and other experiments, and scout the path to topologically protected states that are of interest for quantum computing. We illustrate the importance of the superconductor-semiconductor interface quality and sketch out where further progress in material...
Helicity is a classically conserved quantity which can be used, in addition to and independently of the (vector) charge and chirality, to characterize thermodynamic ensembles of massless Dirac fermions. We identify a symmetry of the Dirac Lagrangian which is responsible, via the Noether theorem, to the classical conservation of the helicity current...
We consider a setup consisting of two coupled sheets of bilayer graphene in the regime of strong spin-orbit interaction, where electrostatic confinement is used to create an array of effective quantum wires. We show that for suitable interwire couplings the system supports a topological insulator phase exhibiting Kramers partners of gapless helical...
A space-time dependent node separation in Weyl semimetals acts as an axial vector field. Coupled with domain wall motion in magnetic Weyl semimetals, this induces axial electric and magnetic fields localized at the domain wall. We show how these fields can activate the axial (chiral) anomaly and provide a direct experimental signature of it. Specif...
