Topological phases have recently witnessed rapid progress in non-Hermitian systems. Here we study a one-dimensional Aubry-Andr\'e-Harper (AAH) model with imaginary periodic or quasiperiodic modulations. We demonstrate that the off-diagonal AAH models can host zero-energy modes at edges. In contrast to Hermitian case, mode be localized only one edge. Such topological phase corresponds existence of quarter winding number defined by eigenenergy momentum space. further find coexistence located...

Dynamical quantum phase transitions are closely related to equilibrium for ground states. Here, we report an experimental observation of a dynamical transition in spinor condensate with correspondence excited state diagram, instead the one. We observe that quench dynamics exhibits non-analytical change respect parameter final Hamiltonian absence corresponding there. make connection between this singular point and highest energy level subspace zero spin magnetization Hamiltonian. further show...

We study disorder effects in a two-dimensional system with chiral symmetry and find that can induce quadrupole topological insulating phase (a higher-order moments) from topologically trivial phase. Their properties manifest invariant defined based on effective boundary Hamiltonians, the moment, zero-energy corner modes. gapped gapless phases Griffiths regime. In phase, all states are localized, while regime, at zero energy become multifractal. further apply self-consistent Born...

We study amorphous systems with completely random sites and find that, through constructing exploring a concrete model Hamiltonian, such system can host an exotic phase of topological metal in three dimensions. In contrast to the traditional Weyl semimetals, metals break translational symmetry, thus they cannot be characterized by first Chern number defined based on momentum space band structures. Instead, their properties will manifest Bott index Hall conductivity as well surface states. By...

Higher-order topological insulators are established as crystalline protected by symmetries. One celebrated example is the second-order insulator in three dimensions that hosts chiral hinge modes Since amorphous solids ubiquitous, it important to ask whether such a can exist an system without any spatial order. Here we predict existence of secondorder insulating phase symmetry. Such manifests winding number quadrupole moment, quantized longitudinal conductance and states. Furthermore, stark...

Higher-order topological phases of matter have been extensively studied in various areas physics. While the Aubry-Andr\'e-Harper model provides a paradigmatic example to study phases, it has not explored whether generalized can exhibit higher-order phenomenon. Here, we construct two-dimensional insulator with chiral symmetry based on model. We find coexistence zero-energy and nonzero-energy corner-localized modes. The former is protected by quantized quadrupole moment, while latter first...

Non-Hermitian topological systems have been shown to exhibit many interesting properties. However, due the presence of complex energy spectra and non-Hermitian skin effect (NHSE), edge states will be dynamically unstable unresolvable from bulk which are also localized at boundaries. Here we propose a one-dimensional nonreciprocal superlattice model in phases solely induced by modulated asymmetric hopping amplitude. Most importantly, can obtain robust real spectra, meanwhile, eliminate NHSE...

Symmetries play a crucial role in the classification of topological phases matter. Although recent studies have established powerful framework to search for and classify based on symmetry indicators, there exists large class fragile topology beyond description. The Euler characterizing two-dimensional real wave functions is an archetypal underlying some important properties, such as non-Abelian braiding crossing nodes higher-order topology. However, minimum model topology, insulator...

Extracellular vesicles (EVs) are important paracrine mediators derived from various cells and biological fluids, including plasma, that capable of inducing regenerative effects by transferring bioactive molecules such as microRNAs (miRNAs). This study investigated the effect mesenchymal stem cell-derived extracellular (MSC-EVs) isolated umbilical cord blood human plasma-derived (UCB-EVs) on wound healing scar formation reduction. Spatial transcriptomics (ST) was used to MSC-EVs UCB-EVs...

A dynamical quantum phase transition can be characterized by a nonanalytic change in the quench dynamics when parameter governing Hamiltonian is varied. Such typically only shows up long-time for extensive systems with short-range couplings. We analyze model of spin-1 particles effectively infinite-range couplings and demonstrate that this system occurs local observables short-time durations even large size. experimentally realize observe an antiferromagnetic spinor Bose-Einstein condensate...

Recent theoretical studies predict that structural disorder, serving as a bridge connecting crystalline material to an amorphous material, can induce topological insulator from trivial phase. However, experimentally observe such phase transition is very challenging due the difficulty in controlling disorder quantum material. Given experimental realization of randomly positioned Rydberg atoms, system naturally suited studying induced transitions and phases. Motivated by development, we study...

A second-order topological insulator in three dimensions refers to a with gapless states localized on the hinges, which is generalization of traditional surfaces. Here we theoretically demonstrate existence stable solitons hinges when nonlinearity involved. By means systematic numerical study, find that soliton has strong localization real space and propagates along hinge unidirectionally without changing its shape. We further construct an electric network simulate insulator. When nonlinear...

Modern theory of electric polarization is formulated by the Berry phase, which, when quantized, leads to topological phases matter. Such a formulation has recently been extended higher multipole moments, through discovery so-called quadupole insulator. It established classical electromagnetic that in two-dimensional material quantized properties for insulator should satisfy basic relation. Here we discover new type quadrupole (dubbed type-II) violates this relation due breakdown...

Controllability of ultracold atomic gases has reached an unprecedented level, allowing for experimental realization the long-sought-after Thouless pump, which can be interpreted as a dynamical quantum Hall effect. On other hand, Weyl semimetals and nodal line with touching points rings in band structures have sparked tremendous interest various fields past few years. Here, we show that 4D rings, are protected by first Chern number on parameter surface formed quasi-momentum time, emerge...

The Kibble-Zurek mechanism provides a unified theory to describe the universal scaling laws in dynamics when system is driven through second-order quantum phase transition. However, for first-order transitions, usually not applicable. Here, we experimentally demonstrate and theoretically analyze power-law of spin-1 condensate across transition slowly from polar an antiferromagnetic phase. We show that this can be described by generalized mechanism. Furthermore, measuring spin population,...

Shiba bands formed by overlapping Yu-Shiba-Rusinov subgap states in magnetic impurities on a superconductor play an important role for realizing topological superconductors. Here, we theoretically demonstrate the existence of gapless magnetically doped $s$-wave superconducting surface with Rashba spin-orbit coupling presence weak in-plane field. Such develop from gapped through Lifshitz phase transitions accompanied second-order quantum intrinsic thermal Hall conductance. We also find...

The fractional quantum Hall effect is a well-known demonstration of strongly correlated topological phases in two dimensions. However, the extension this phenomenon into three-dimensional context has yet to be achieved. Recently, integer based on Weyl orbits been experimentally observed semimetallic material under magnetic field. This motivates us ask whether can give rise when their Landau level partially filled presence interactions. Here we theoretically demonstrate that states emerge...

Heat generated as a result of the breakdown an adiabatic process is one central concepts thermodynamics. In isolated systems, heat can be defined energy increase due to transitions between distinct levels. Across second-order quantum phase transition (QPT), predicted theoretically exhibit power-law scaling, but it significant challenge for experimental observation. addition, remains elusive whether scaling exist first-order QPT. Here we experimentally observe in spinor condensate when system...

Yang, Y.1; Takhar, M.1; Hollander, Z.1; Lin, D.2; Wilson-mcmanus, J.1; Ng, R. T.2; Keown, P. A.3; Mcmaster, M.4; Mcmanus, B.1; Tebbutt, S. J.4 Author Information