手征p波超导体中极性克尔效应的本征和非本征起源

来自极向克尔效应的$A$V$_3$Sb$_5$中轨道通量相的约束

Constraints on the orbital flux phase in $A$V$_3$Sb$_5$ from polar Kerr effect

本研究针对Kagome金属$A$V$_3$Sb$_5$中电荷密度波序的本质争议，通过对称性分析和三六角轨道通量相的计算，解释了极向克尔效应测量的矛盾结果，为阐明其CDW序提供了理论依据。

Nature of extrinsic and intrinsic self-trapping of charge carriers in underdoped cuprate high-$T_\text{c}$ superconductors

Nature of extrinsic and intrinsic self-trapping (ST) of charge carriers in cuprates have been studied theoretically. The binding energies and radii of the extrinsic and intrinsic large polarons and bipolarons in cuprates are calculated variationally using the continuum model and adiabatic approximation. We have shown that the extrinsic and intrinsic three-dimensional (3D) large bipolarons exist in underdoped cuprates at $η=\varepsilon_{\infty}/\varepsilon_0<0.127$ and $η<0.138$, respectively [where $\varepsilon_{\infty}$ ($\varepsilon_0$) is the optic (static) dielectric constant].

非常规超导体Sr $_2$ RuO $_4$中的克尔转动

The Kerr rotation in the unconventional superconductor Sr$_2$RuO$_4$

Sr $_2$ RuO $_4$超导相的克尔旋转测量结果的解释是一个有争议的话题。已经提出了内在和外在的机制，它已被认为是内在的响应消失的对称性。我们专注于内在的贡献，并澄清文献中的几个相互矛盾的结果。在对称性考虑和详细计算的基础上，我们证明了本征克尔信号在一般的多带系统中是不被禁戒的，但在近红外区具有丰富的结构。我们区分不同的光学跃迁所确定的超导能隙（远红外）和轨道间耦合的正常状态（近红外）。我们认为，低频跃迁不有助于霍尔电导率，而只有轨道间跃迁在近红外区作出贡献。最后，我们讨论了困难的光学霍尔电导率的计算连接到克尔角的实验测量。我们将比较可能导致相互矛盾的结果的不同近似值。

Polar Kerr effect from a time-reversal symmetry breaking unidirectional charge density wave

We analyze the Hall conductivity $σ_{xy}(ω)$ of a charge ordered state with momentum $\mathbf{Q}=(0,2Q)$ and calculate the intrinsic contribution to the Kerr angle $Θ_K$ using the fully reconstructed tight-binding band structure for layered cuprates beyond the low energy hot spots model and particle hole symmetry. We show that such a unidirectional charge density wave (CDW), which breaks time reversal symmetry as recently put forward by Wang and Chubukov [Phys. Rev. B {\bf 90}, 035149 (2014)], leads to a nonzero polar Kerr effect as observed experimentally. In addition, we model a fluctuating …

多带自旋轨道耦合超导体中的极向克尔效应

Polar Kerr Effect in Multiband Spin-Orbit Coupled Superconductors

本研究通过理论分析钌酸锶超导相的克尔谱，揭示自旋轨道耦合调控的准一维轨道杂化主导霍尔响应，其时间反演对称性破缺可解释克尔角现象，数值结果匹配实验，为相关机制提供新见解。

Probing time reversal symmetry breaking topological superconductivity in twisted double layer copper oxides with polar Kerr effect

Recent theoretical work predicted emergence of chiral topological superconducting phase with spontaneously broken time reversal symmetry in a twisted bilayer composed of two high-$T_c$ cuprate monolayers, such as Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$. Here we identify large intrinsic Hall response that can be probed through the polar Kerr effect measurement as a convenient signature of the $\mathcal{T}$-broken phase. Our modelling predicts the Kerr angle $θ_K$ to be in the range of 10-100 $μ$rad, which is a factor of $10^3-10^4$ times larger than what is expected for the leading chiral supercondutor c…

非常规超导体中时间约束对称性破缺的极克尔效应

Polar Kerr Effect as Probe for Time-Reversal Symmetry Breaking in Unconventional Superconductors

在过去的一年里，随着更多的系统被预测拥有这样的状态，对非常规超导体中时间反演对称性破缺（TRSB）的研究得到了加强。继我们的开创性研究的TRSB状态的Sr $_2$ RuO $_4$使用磁光探针，我们开始了系统的研究，这些候选系统的其他几个。我们研究的主要仪器是我们最近开发的Sagnac磁光干涉仪。该仪器可以测量磁光法拉第或克尔效应，在低至100 mK的温度下具有前所未有的10纳米弧度的灵敏度。本文综述了我们近年来在几个系统中对TRSB的研究，着重于对高温超导体赝能隙态和超导体/铁磁体邻近结构中的逆邻近效应的研究。

CsV₃Sb₅的高分辨率极向克尔效应研究：电荷有序转变下时间反演对称性破缺的检验

High Resolution Polar Kerr Effect Studies of CsV${}_3$Sb${}_5$: Tests for Time Reversal Symmetry Breaking Below the Charge Order Transition

本研究利用两种1550 nm零面积环Sagnac干涉仪测量CsV₃Sb₅单晶的极向克尔效应，在30纳弧度噪声限内未观测到自发时间反演对称性破缺信号，结合有限磁场下的抗磁位移结果，推断其电荷有序态不太可能破缺时间反演对称性。

候选时间反演对称性破缺超导体BiNi中的太赫兹波段偏振旋转

Terahertz range polarization rotation in the candidate time-reversal symmetry breaking superconductor BiNi

本研究利用高精度太赫兹偏振测量技术，在零磁场下的BiNi双层超导体中观察到了迄今最小的偏振旋转和数百微弧度的低频克尔旋转，证实了时间反演对称性破缺，并通过分析支持了多带超导情景。