Zobrazeno 1 - 10
of 269
pro vyhledávání: '"Akhmerov, A. R."'
A common technique in the study of complex quantum-mechanical systems is to reduce the number of degrees of freedom in the Hamiltonian by using quasi-degenerate perturbation theory. While the Schrieffer--Wolff transformation achieves this and constru
Externí odkaz:
http://arxiv.org/abs/2404.03728
Axial vectors, such as current or magnetization, are commonly used order parameters in time-reversal symmetry breaking systems. These vectors also break isotropy in three dimensional systems, lowering the spatial symmetry. We demonstrate that it is p
Externí odkaz:
http://arxiv.org/abs/2310.18400
The non-Hermitian skin effect is a phenomenon in which an extensive number of states accumulates at the boundaries of a system. It has been associated to nontrivial topology, with nonzero bulk invariants predicting its appearance and its position in
Externí odkaz:
http://arxiv.org/abs/2308.00776
We present a systematic method to design arbitrary energy-phase relations using parallel arms of two series Josephson tunnel junctions each. Our approach employs Fourier engineering in the energy-phase relation of each arm and the position of the arm
Externí odkaz:
http://arxiv.org/abs/2307.04830
Publikováno v:
SciPost Phys. 16, 044 (2024)
Braiding of Majorana states demonstrates their non-Abelian exchange statistics. One implementation of braiding requires control of the pairwise couplings between all Majorana states in a trijunction device. To have adiabaticity, a trijunction device
Externí odkaz:
http://arxiv.org/abs/2307.03299
Publikováno v:
Phys. Rev. B 109, L081103 (2024)
We develop a theory of magnetic breakdown (MB) near high-order saddle points in the dispersions of two-dimensional materials, where two or more semiclassical cyclotron orbits approach each other. MB occurs due to quantum tunneling between several tra
Externí odkaz:
http://arxiv.org/abs/2303.07447
Publikováno v:
SciPost Phys. 16, 120 (2024)
Disorder can localize the eigenstates of one-dimensional non-Hermitian systems, leading to an Anderson transition with a critical exponent of 1. We show that, due to the lack of energy conservation, the dynamics of individual, real-space wave packets
Externí odkaz:
http://arxiv.org/abs/2301.07370
Publikováno v:
SciPost Phys. 15, 114 (2023)
We derive a $\mathbb{Z}_4$ topological invariant that extends beyond symmetry eigenvalues and Wilson loops and classifies two-dimensional insulators with a $C_4 \mathcal{T}$ symmetry. To formulate this invariant, we consider an irreducible Brillouin
Externí odkaz:
http://arxiv.org/abs/2209.00029
Publikováno v:
Phys. Rev. B 106, 235413 (2022)
We consider the propagation of electrons in a lattice with an anisotropic dispersion in the $x$--$y$ plane (lattice constant $a$), such that it supports open orbits along the $x$-axis in an out-of-plane magnetic field $B$. We show that a point source
Externí odkaz:
http://arxiv.org/abs/2207.10066
Publikováno v:
SciPost Phys. 14, 047 (2023)
Josephson junctions in a two-dimensional electron gas with spin-orbit coupling are a promising candidate to realize topological superconductivity. While it is known that the geometry of the junction strongly influences the size of the topological gap
Externí odkaz:
http://arxiv.org/abs/2205.05689