Detecting Topological Quantum Phase Transitions via the c-Function

Detecting Topological Order at Finite Temperature Using Entanglement Negativity

We propose a diagnostic for finite temperature topological order using `topological entanglement negativity', the long-range component of a mixed-state entanglement measure. As a demonstration, we study the toric code model in $d$ spatial dimension for $d$=2,3,4, and find that when topological order survives thermal fluctuations, it possesses a non-zero topological entanglement negativity, whose value is equal to the topological entanglement entropy at zero temperature. Furthermore, we show that the Gibbs state of 2D and 3D toric code at any non-zero temperature, and that of 4D toric code abov…

A proposal for detecting second order topological quantum phase

Gaussian linking of a semiclassical path of a charged particle with a magnetic flux tube is responsible for the Aharonov-Bohm effect, where one observes interference proportional to the magnitude of the enclosed flux. We construct quantum mechanical wave functions where semiclassical paths can have second order linking to two magnetic flux tubes, and show there is interference proportional to the product of the two fluxes.

Detecting topological sectors in continuum Yang-Mills theory and the fate of BRST symmetry

In this work, motivated by Laplacian type center gauges in the lattice, designed to avoid the Gribov problem, we introduce a new family of gauge fixings for pure Yang-Mills theories in the continuum. This procedure separates the partition function into partial contributions associated with different sectors, containing center vortices and correlated monopoles. We show that, on each sector, the gauge fixed path-integral displays a BRST symmetry, however, it cannot be globally extended due to sector dependent boundary conditions on the ghost fields. These are nice features as they would permit t…

在全息外尔半金属中通过多体纠缠探测拓扑相变和各向异性

Detecting Topological Transitions and Anisotropy through Multipartite Entanglement in Holographic Weyl Semimetals

通过计算全息外尔半金属中的三体和四体纠缠量（如条件互信息、纠缠楔截面等），发现这些量在拓扑相变临界点附近呈现显著特征，且各向异性行为可区分拓扑非平凡相与平凡相。

纠缠熵在探测热相变方面的局限性

Limitations of entanglement entropy in detecting thermal phase transitions

本文研究全息规范理论中纠缠熵探测热相变的能力，发现其可识别等离子体相间转变并确定临界指数，但难以探测通向有隙相的相变。

Detecting and distinguishing topological defects in future data from the CMBPol satellite

The proposed CMBPol mission will be able to detect the imprint of topological defects on the cosmic microwave background (CMB) provided the contribution is sufficiently strong. We quantify the detection threshold for cosmic strings and for textures, and analyse the satellite's ability to distinguish between these different types of defects. We also assess the level of danger of misidentification of a defect signature as from the wrong defect type or as an effect of primordial gravitational waves. A 0.002 fractional contribution of cosmic strings to the CMB temperature spectrum at multipole ten…