Search

In the paper, based on recent studies on $T\bar{T}$ deformation of 2D field theory with supersymmetry, we investigate the deformed correlation functions in $\mathcal{N}=(1,1)$ and $\mathcal{N}=(2,2)$ 2D superconformal field theories. Up to the leading order in perturbation theory, we compute the correlation functions under $T\bar{T}$ deformation. The correlation functions in these undeformed theories are almost known, and together with the help of superconformal Ward identity in $\mathcal{N}=(1,1)$ and $\mathcal{N}=(2,2)$ theories respectively we can obtain the correlation functions with operator $T\bar{T}$ inserted. Finally, by employing dimensional regularization, we can work out the integrals in the first order perturbation. The study in this paper extends previous works on the correlation functions of $T\bar{T}$ deformed bosonic CFT to the supersymmetric case., Comment: 43 pages, published version

Tensor networks are powerful techniques that widely used in condensed matter physics. In this language, the wave function of a quantum manybody system is described by a network of tensors with specific entanglement structures. Recently, it is shown that tensor network can generate the anti-de Sitter (AdS) geometry by using the entanglement renormalization approach. However, whether the dynamical connections can be found between the tensor network and the gravity is an important unsolved problem. In this paper, we give a novel proposal to integrate ideas from tensor networks, entanglement entropy, canonical quantization of quantum gravity and the holographic principle and argue that the gravitational dynamics can be generated from a tensor network if the wave function of the latter satisfies the Wheeler-DeWitt equation., Comment: 10 pages

Weyl semimetals exhibitinging the topologically nontrivial touching points in electronic band dispersion of solids pave the wave way to novel electronic devices and functionalities. Here, we demonstrate the signature of topologically nontrivial Weyl points (WPs) in phonon dispersion of solids through a first-principles investigations. ofT noncentrosymmetric wurtzite CuI (cuprous iodide at high temperature). These type-II phononic WP in phonon dispersion of wurtzite CuI is manifested in noncentrosymmetric wurtzite CuI by six pairs of the nontrivial touching points in the k_z=0.0 plane. The ideal WPs in phonon dispersion are completely isolated from bulk phonon continuum, are different distinct from many type-II WPs in electronic band dispersion of solids associated with the overlapping band states. The opposite chirality of Weyl phonon nodes with quantized Berry curvature are utilized forproduces Weyl phonon Hall effect, in analogous analogy towith valley Hall effect of electrons. Such ideal type-II Weyl phonons are phase is readily observable in experiment, and could provideing a unique platform to study novel thermal transport properties different distinct from that in type-I Weyl phonons phase.

The topological states of matters arising from the nontrivial magnetic configuration provide a better understanding of physical properties and functionalities of solid materials. Such studies benefit from the active control of spin orientation in any solid, which is yet known to rarely take place in the two-dimensional (2D) limit. Here we demonstrate by the first-principles calculations that spin-orientation dependent topological states can appear in the geometrically frustrated monolayer antiferromagnet. Different topological states including quantum anomalous Hall (QAH) effect and time-reversal-symmetry (TRS) broken quantum spin Hall (QSH) effect can be obtained by changing spin orientation in the NiTl2S4 monolayer. Remarkably, the dilated nc-AFM NiTl2S4 monolayer gives birth to the QAH effect with hitherto reported largest number of quantized conducting channels (Chern number C = -4) in 2D materials. Interestingly, under tunable chemical potential, the nc-AFM NiTl2S4 monolayer hosts a novel state supporting the coexistence of QAH and TRS broken QSH effects with a Chern number C = 3 and spin Chern number C_s = 1. This work manifests a promising concept and material realization toward topological spintronics in 2D antiferromagnets by manipulating its spin degree of freedom.

Using the symmetry of the near-horizon geometry and applying quantum field theory of a complex scalar field, we study the spontaneous pair production of charged scalars from near-extremal rotating, electrically and/or magnetically charged black holes. Analytical expressions for pair production, vacuum persistence and absorption cross section are found, and the spectral distribution is given a thermal interpretation. The pair production in near-extremal black holes has a factorization into the Schwinger effect in AdS and Schwinger effect in Rindler space, measuring the deviational from extremality. The associated holographical correspondence is confirmed at the 2-point function level by comparing the absorption cross section ratio as well as the pair production rate both from the gravity and the conformal field theories. The production of monopoles is discussed., Comment: 9 pages, contribution to the proceedings of 15th Marcel Grossmann Meeting (MG15)

The coupling of monochromatic light fields and solids introduces nonequilibrium Floquet states, offering opportunities to create and explore new topological phenomena. Using combined first-principles and Floquet analysis we show that one can freely engineer Floquet-Dirac fermions (FDFs) in graphene by tuning the frequency and intensity of linearly polarized light. Not only type-II FDFs are created, but they also coexist with type-I FDFs near the Fermi level. Intriguingly, novel topologically nontrivial edge states connecting type-I and type-II Floquet-Dirac points emerge in photodriven graphene, providing an ideal channel to realize electron transport between the two types of Dirac states. Simulating time- and angle-resolved photoelectron spectroscopy suggests that the new coexisting state of type-I and type-II fermions is experimentally accessible. This work implies that a rich FDF phenomenon can be engineered in atomically thin graphene, hinting for developments of novel optoelectronic and quantum computing devices., Comment: Accepted by Phys. Rev. B

In this paper we study the R\'{e}nyi entropy of 2D massless free fermions perturbed by the $T\bar{T}$ term and the $J\bar{T}$ term at the first order perturbation. Three cases, the vacuum state of infinite size system with $T\bar{T}$ perturbation, the excited states of finite size system with $T\bar{T}$ perturbation, and the vacuum state of infinite size system with $J\bar{T}$ perturbation, are analyzed. We use the bosonization approach to calculate the perturbative expansions of R\'{e}nyi entropy. In the bosonization language the twist operator is known explicitly, with which the computation of correlators in the perturbative expansion can be simply performed. Moreover, we show that the $T\bar{T}$ and $J\bar{T}$ terms have a simple form and are similar with each other. For the first and third cases, we reproduce the known results for R\'{e}nyi entropy using the bosonization method. While for the second case, we obtain new results for the excited states., Comment: 22 pages