Exceptional odd-frequency pairing in non-Hermitian superconducting systems

非常态安德鲁夫能谱和超流电流在p波非厄运接头中

Exceptional Andreev spectrum and supercurrent in p-wave non-Hermitian Josephson junctions

研究p波非厄运约瑟夫森接头中安德鲁夫能谱和超流电流的特性，揭示例外点与马约拉纳零模的关系及非厄运性对传输特性的影响。

Topological exceptional surfaces in non-Hermitian systems with parity-time and parity-particle-hole symmetries

We study a topological band degeneracy in non-Hermitian systems with parity-time ($PT$) and parity-particle-hole ($CP$) symmetries. In $d$-dimensional non-Hermitian systems, it is shown that $(d-1)$-dimensional exceptional surfaces can appear from band touching thanks to $PT$ or $CP$ symmetry. We investigate the topological stability and zero-gap quasiparticles for the exceptional surfaces due to the band degeneracy. We also demonstrate the band degeneracy by using lattice models of a topological semimetal and a superconductor.

非厄米多端相位偏置约瑟夫森结

Non-Hermitian multiterminal phase-biased Josephson junctions

本文研究多超导体形成的非厄米约瑟夫森结，发现由超导相位与非厄米性共同决定的奇异点，并揭示其在拓扑保护、超流增强及高维非厄米超导现象中的潜力。

Resonant generation of $p$-wave Cooper pair in non-Hermitian Kitaev chain at exceptional point

We investigate a non-Hermitian extension of Kitaev chain by considering imaginary $p$-wave pairing amplitudes. The exact solution shows that the phase diagram consists two phases with real and complex \ Bogoliubov-de-gens spectra, associated with $\mathcal{PT}$-symmetry breaking, which is separated by a hyperbolic exceptional line. The exceptional points (EPs) correspond to a specific Cooper pair state $( 1+c_{k}^{\dagger }c_{-k}^{\dagger }) \left\vert 0\right\rangle $\ with movable $k$ when the parameters vary along the exceptional line. The non-Hermiticity around EP supports resonant generat…

Theory of superconductivity with non-Hermitian and parity-time reversal symmetric cooper pairing symmetry

Recently developed parity (P) and time-reversal (T) symmetric non-Hermitian systems govern a rich variety of new and characteristically distinct physical properties, which may or may not have a direct analog in their Hermitian counterparts. We study here a non-Hermitian, PT-symmetric superconducting Hamiltonian that possesses real quasiparticle spectrum in the PT-region of the Brillouin zone. Within a single-band mean-field theory, we find that real quasiparticle energies are possible when the superconducting order parameter itself is either Hermitian or anti-Hermitian. Within the correspondin…

非厄米双带BCS模型中零奇异点处迈斯纳效应的破坏

Breakdown of the Meissner effect at the zero exceptional point in non-Hermitian two-band BCS model

本研究从非厄米双带BCS模型推导复金兹堡-朗道模型，发现其迈斯纳效应在奇异点处破坏，类似于希格斯机制，但间隙参数保持有限。