Related papers: Probing Fermi sea topology by Andreev state transp…
We develop the theory of an Andreev junction, which provides a method to probe the intrinsic topology of the Fermi sea of a two-dimensional electron gas (2DEG). An Andreev junction is a Josephson $\pi$ junction proximitizing a ballistic…
A Fermi gas of non-interacting electrons, or ultra-cold fermionic atoms, has a quantum ground state defined by a region of occupancy in momentum space known as the Fermi sea. The Euler characteristic $\chi_F$ of the Fermi sea serves to…
The Fermi sea of a metal can host exotic quantum topology, which governs its conductance quantization and is characterized by the Euler characteristic ($\chi_F$). In contrast to the well-known band topology, which is determined by the…
Pauli's exclusion principle forces fermions to occupy distinct quantum states, creating a filled region of momentum space at low temperature, the Fermi sea, whose topology governs the system's response to perturbations and the nature of its…
The geometry of Fermi sea hosts a unique form of quantum topology that governs the conductance quantization of metal and is characterized by the Euler characteristic $\chi_F$, offering a new perspective in the study of topological quantum…
The Fermi sea topology is characterized by the Euler characteristics $\chi_F$. In this paper, we examine how $\chi_F$ of the metallic state is inhereted by the topological invariant of the superconducting state. We establish a…
The energy of an Andreev bound state in a clean normal metal in contact with two superconductors disperses with the difference $\Delta \phi$ in the superconducting phase between the superconductors in much the same way as the energies of…
We study coherent transport and bound-state formation of Bogoliubov quasiparticles in a high-mobility In$_{0.75}%$Ga$_{0.25}$As two-dimensional electron gas (2DEG) coupled to a superconducting Nb electrode by means of a quantum point…
We describe the proximity effect in a short disordered metallic junction between three superconducting leads. Andreev bound states in the multi-terminal junction may cross the Fermi level. We reveal that for a quasi-continuous metallic…
We introduce a non-linear frequency dependent D+1 terminal conductance that characterizes a D dimensional Fermi gas, generalizing the Landauer conductance in D=1. For a 2D ballistic conductor we show that this conductance is quantized and…
A normal conductor placed in good contact with a superconductor can inherit its remarkable electronic properties. This proximity effect microscopically originates from the formation in the conductor of entangled electron-hole states, called…
Recent experiments have observed hints of hydrodynamic electron flow in a number of materials, not all of which have an isotropic Fermi surface. We revisit these experiments in $\mathrm{PdCoO}_2$, a quasi-two-dimensional material whose…
We experimentally investigate charge transport through the interface between a niobium superconductor and a three-dimensional WTe$_2$ Weyl semimetal. In addition to classical Andreev reflection, we observe sharp non-periodic subgap…
We theoretically study transport signatures associated with a spontaneous 2-valley to 1-valley quantum phase transition in a two-dimensional electron gas (2DEG) tuned by decreasing the 2D carrier density, as claimed in a recent experiment…
Clean two-dimensional Fermi liquids are now known to exhibit an intermediate \emph{tomographic} regime, between ballistic and Navier--Stokes transport, caused by the anomalously slow relaxation of parity-odd multipolar deformations of the…
We report electrical conductivity $\sigma$ measurements on a range of two-dimensional electron gases (2DEGs) of varying linear extent. Intriguingly, at low temperatures ($T$) and low carrier density ($n_{\mathrm{s}}$) we find the behavior…
We consider the description of a Fermi gas of free electrons given by the Boltzmann--Fermi--Dirac equation, and aim at providing a precise mathematical understanding of the Fermi ground state and its first-order approximation of excited…
We consider a two-dimensional electron gas (2DEG) in the Quantum Hall regime in the presence of a Zeeman field, with the Fermi level tuned to filling factor $\nu=1$. We show that, in the presence of spin-orbit coupling, contacting the 2DEG…
We investigate the influence of electron--electron interactions on the density of states of a ballistic two--dimensional electron gas. The density of states is determined nonperturbatively by means of path integral techniques allowing for…
We construct a theory for low-energy quantum transport in normal$\mid$superconductor junctions involving the recently discovered iron-based high-$T_c$ superconductors. We properly take into account both Andreev bound surface states and the…