Non-Hermitian topological Mott insulators in one-dimensional fermionic superlattices

Liu, Tao; He, James Jun; Yoshida, Tsuneya; Xiang, Ze-Liang; Nori, Franco

doi:10.1103/physrevb.102.235151

Cited by 67 publications

(31 citation statements)

References 111 publications

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“…Such results provide important advances to understand the nontrivial interplay between disorder and non-Hermiticity, which is currently a hot area of research [29,[53][54][55][56][57][58][59][60][61]64,67,69,71,73,74]. The kind of non-Hermitian Hamiltonian with asymmetric hopping amplitudes considered in this work could be realized in synthetic matter using, for example, photonic systems [53,64,86,87], topoelectrical circuits [88], mechanical metamaterials [89], or in continuously measured ultracold atom systems with reservoir engineering [55,90].…”

Section: Discussionmentioning

confidence: 99%

Phase transitions in a non-Hermitian Aubry-André-Harper model

Longhi

2021

Phys. Rev. B

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The Aubry-André-Harper model provides a paradigmatic example of aperiodic order in a one-dimensional lattice displaying a delocalization-localization phase transition at a finite critical value V c of the quasiperiodic potential amplitude V . In terms of the dynamical behavior of the system, the phase transition is discontinuous when one measures the quantum diffusion exponent δ of wave-packet spreading, with δ = 1 in the delocalized phase V < V c (ballistic transport), δ 1/2 at the critical point V = V c (diffusive transport), and δ = 0 in the localized phase V > V c (dynamical localization). However, the phase transition turns out to be smooth when one measures, as a dynamical variable, the speed v(V ) of excitation transport in the lattice, which is a continuous function of potential amplitude V and vanishes as the localized phase is approached. Here we consider a non-Hermitian extension of the Aubry-André-Harper model, in which hopping along the lattice is asymmetric, and show that the dynamical localization-delocalization transition is discontinuous, not only in the diffusion exponent δ, but also in the speed v of ballistic transport. This means that even very close to the spectral phase transition point, rather counterintuitively, ballistic transport with a finite speed is allowed in the lattice. Also, we show that the ballistic velocity can increase as V is increased above zero, i.e., surprisingly, disorder in the lattice can result in an enhancement of transport.

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Section: Discussionmentioning

confidence: 99%

Phase transitions in a non-Hermitian Aubry-André-Harper model

Longhi

2021

Phys. Rev. B

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“…Thus, it is of fundamental interest to explore non-Hermitian phenomena in many-body systems with strong interactions . Most of the existing studies on this subject are focused on the issues of non-Hermitian many-body localization [49][50][51][52] and the non-Hermitian skin effect [54][55][56][57][58][59][60][61][62]. However, many-body interaction effects, especially on bulk fermionic properties, remain largely unexplored even in simple models.…”

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confidence: 99%

Symmetry breaking and spectral structure of the interacting Hatano-Nelson model

Zhang¹,

Denner²,

Bzdušek³

et al. 2022

Preprint

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“…We consider a BEC in a symmetric double-well trapping potential with N weakly interacting atoms, and assume that the atoms are coherently transferred from one well to the other with laser-induced tunable nonreciprocal hopping [44]. Within the two-mode approximation [55][56][57][58][63][64][65][66], the system can be described by the following two-site Bose-Hubbard Hamiltonian with the nonreciprocal hopping [13][14][15][16][17][18][19][20][21][22][23][24][25][26]:…”

Section: Modelmentioning

confidence: 99%

“…Apart from the gain-and-loss effect, the nonreciprocity is another kind of non-Hermiticity. It has been theoretically revealed that nonreciprocal systems exhibit exotic topological and localization physics [4,5,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. In experiments, the nonreciprocity can be realized in classical electric circuits [27,28], optical systems [29][30][31][32][33][34][35][36][37], and optomechanical devices [38][39][40][41][42][43].…”

Section: Introductionmentioning

confidence: 99%

Interplay of nonreciprocity and nonlinearity on mean-field energy and dynamics of a Bose-Einstein condensate in a double-well potential

Zhang

et al. 2021

Front. Phys.

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We investigate the mean-field energy spectrum and dynamics in a Bose-Einstein condensate in a double-well potential with non-Hermiticity from the nonreciprocal hopping, and show that the interplay of nonreciprocity and nonlinearity leads to exotic properties. Under the two-mode and mean-field approximations, the nonreciprocal generalization of the nonlinear Schrödinger equation and Bloch equations of motion for this system are obtained. We analyze the PT phase diagram and the dynamical stability of fixed points. The reentrance of PT -symmetric phase and the reformation of stable fixed points with increasing the nonreciprocity parameter are found. Besides, we uncover a linear selftrapping effect induced by the nonreciprocity. In the nonlinear case, the self-trapping oscillation is enhanced by the nonreciprocity and then collapses in the PT -broken phase, and can finally be recovered in the reentrant PT -symmetric phase.

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Non-Hermitian topological Mott insulators in one-dimensional fermionic superlattices

Cited by 67 publications

References 111 publications

Phase transitions in a non-Hermitian Aubry-André-Harper model

Phase transitions in a non-Hermitian Aubry-André-Harper model

Symmetry breaking and spectral structure of the interacting Hatano-Nelson model

Interplay of nonreciprocity and nonlinearity on mean-field energy and dynamics of a Bose-Einstein condensate in a double-well potential

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