The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Su...The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Such accidental zero modes should be carefully ruled out in experiment in order to identify the genuine Majorana zero modes.We show that in a spin-orbital coupled multi-band superconductor,such as the iron-selenide superconductor,accidental zero modes indeed arise in the vortex core if the pairing symmetry is the so-called nodeless d-wave(defined in the absence of spin-orbital coupling).Instead,if the pairing sym-metry is s_(++)or s_(+−)with respect to the Fermi pockets split by the spin-orbital coupling,the accidental zero modes do not appear in the limit of weak spin-orbital coupling.Our results are not only important in the experimental identification of Majorana zero modes,but also provide an avenue to pinpoint the pairing symmetry of the iron-selenide superconductor.展开更多
Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,medi...Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,mediated by suitable optical media.There are many emerging photonic applications of spin-orbit interactions(SOI)of light,such as control of the optical wave propagation via the spin,enhanced optical manipulation,and generation of structured optical fields.Unfortunately,current applications are based on symmetric SOI,that is,the behaviours of polarized photons with two opposite spins are opposite,leading to the limit of spin-based multiplexers.The symmetry of SOI can be broken in our proposed metasurfaces,consisting of spatially varying birefringence,which can arbitrarily and independently build SOI for two opposite spins without reduction of optical energy usage.We obtain three kinds of dual-functional metasurfaces at visible and infrared wavelengths with high efficiency.Our concept of generation of asymmetric SOI for two spins,using anisotropic metasurfaces,will open new degrees of freedoms for building new types of spin-controlled multifunctional shared-aperture devices for the generation of complex structured optical fields.展开更多
钙钛矿氧化物异质界面中二维电子气(two-dimensional electron gas,2DEG)与界面超导性的发现使其成为研究热点之一.近年来,氧化物界面研究取得突破性进展,除了传统的LaAlO_(3)/SrTiO_(3)(LAO/STO)界面,2021年在KTaO_(3)(KTO)界面也发现...钙钛矿氧化物异质界面中二维电子气(two-dimensional electron gas,2DEG)与界面超导性的发现使其成为研究热点之一.近年来,氧化物界面研究取得突破性进展,除了传统的LaAlO_(3)/SrTiO_(3)(LAO/STO)界面,2021年在KTaO_(3)(KTO)界面也发现超导性,其超导转变温度(Tc)较LAO/STO高出一个数量级,约为2 K,引起广泛关注.与STO界面体系相比,KTO氧化物界面显现出高载流子迁移率、强自旋轨道耦合(spin-orbit coupling,SOC)等特点,为理解非常规超导机制和构建新物理特性的研究提供了新途径,使KTO异质界面成为未来电子和自旋电子应用的有力候选者.本文旨在总结近5年KTO界面的最新进展,概述多种氧化物与KTO界面超导的新奇物理现象,并讨论目前研究中尚未解决的问题,为未来研究提供参考.展开更多
基金supported by National Key R&D Program of China(Grant No.2022YFA1403201)and National Natural Science Foundation of China(Grant No.12374147,12274205 and 92365203).
文摘The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Such accidental zero modes should be carefully ruled out in experiment in order to identify the genuine Majorana zero modes.We show that in a spin-orbital coupled multi-band superconductor,such as the iron-selenide superconductor,accidental zero modes indeed arise in the vortex core if the pairing symmetry is the so-called nodeless d-wave(defined in the absence of spin-orbital coupling).Instead,if the pairing sym-metry is s_(++)or s_(+−)with respect to the Fermi pockets split by the spin-orbital coupling,the accidental zero modes do not appear in the limit of weak spin-orbital coupling.Our results are not only important in the experimental identification of Majorana zero modes,but also provide an avenue to pinpoint the pairing symmetry of the iron-selenide superconductor.
基金supported by 973 Program of China (2013CBA01700)National Natural Science Funds (61622508, 61575032)
文摘Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,mediated by suitable optical media.There are many emerging photonic applications of spin-orbit interactions(SOI)of light,such as control of the optical wave propagation via the spin,enhanced optical manipulation,and generation of structured optical fields.Unfortunately,current applications are based on symmetric SOI,that is,the behaviours of polarized photons with two opposite spins are opposite,leading to the limit of spin-based multiplexers.The symmetry of SOI can be broken in our proposed metasurfaces,consisting of spatially varying birefringence,which can arbitrarily and independently build SOI for two opposite spins without reduction of optical energy usage.We obtain three kinds of dual-functional metasurfaces at visible and infrared wavelengths with high efficiency.Our concept of generation of asymmetric SOI for two spins,using anisotropic metasurfaces,will open new degrees of freedoms for building new types of spin-controlled multifunctional shared-aperture devices for the generation of complex structured optical fields.
文摘钙钛矿氧化物异质界面中二维电子气(two-dimensional electron gas,2DEG)与界面超导性的发现使其成为研究热点之一.近年来,氧化物界面研究取得突破性进展,除了传统的LaAlO_(3)/SrTiO_(3)(LAO/STO)界面,2021年在KTaO_(3)(KTO)界面也发现超导性,其超导转变温度(Tc)较LAO/STO高出一个数量级,约为2 K,引起广泛关注.与STO界面体系相比,KTO氧化物界面显现出高载流子迁移率、强自旋轨道耦合(spin-orbit coupling,SOC)等特点,为理解非常规超导机制和构建新物理特性的研究提供了新途径,使KTO异质界面成为未来电子和自旋电子应用的有力候选者.本文旨在总结近5年KTO界面的最新进展,概述多种氧化物与KTO界面超导的新奇物理现象,并讨论目前研究中尚未解决的问题,为未来研究提供参考.
基金supported by the National Natural Science Foundation of China(10676007)Program for New Century Excellent Talents at the University of Fujian Province,China(HX2006-103)~~
