Breakdown of topological Thouless pumping in the strongly interacting regime

Nakagawa, Masaya; Yoshida, Tsuneya; Peters, Robert; Kawakami, Norio

doi:10.1103/physrevb.98.115147

Cited by 49 publications

(49 citation statements)

References 87 publications

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“…The change of the Chern number is clearly seen in our finite-size data and we expect that this U -driven transition should be detectable in a charge-pumping experiment. Different from the fermionic Rice-Mele model [36], we don't observe a breakdown of the charge pump when studying the same quantities as in [36] on finite system sizes. The presence of gapless spin excitations along special points of the pump cycle parameterized by δ may ultimately spoil the quantization of C at large U/t, but we expect that for the first pump cycles that can typically be accessed in a quantum-gas experiment, C, and hence the pumped charge, should remain quantized.…”

Section: Discussioncontrasting

confidence: 57%

“…This implies that the many-body groundstate must remained gapped, such that an adiabatic limit is well- defined. Therefore, there has been great interest in finding insulating quantum phases for both bosonic [36,[39][40][41][42] and fermionic [35,39] systems. Furthermore, one can also establish an analogy to the spin-Quantum Hall effect by studying families of such 1D Hamiltonians with a spin-dependent optical potential [35,39].…”

Section: Introductionmentioning

confidence: 99%

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Quantum phases and topological properties of interacting fermions in one-dimensional superlattices

et al. 2019

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The realization of artificial gauge fields in ultracold atomic gases has opened up a path towards experimental studies of topological insulators and, as an ultimate goal, topological quantum matter in many-body systems. As an alternative to the direct implementation of two-dimensional lattice Hamiltonians that host the quantum Hall effect and its variants, topological charge-pumping experiments provide an additional avenue towards studying many-body systems. Here, we consider an interacting two-component gas of fermions realizing a family of one-dimensional superlattice Hamiltonians with onsite interactions and a unit cell of three sites, whose groundstates would be visited in an appropriately defined charge pump. First, we investigate the grandcanonical quantum phase diagram of individual Hamiltonians, focusing on insulating phases. For a certain commensurate filling, there is a sequence of phase transitions from a band insulator to other insulating phases (related to the physics of ionic Hubbard models) for some members of the manifold of Hamiltonians. Second, we compute the Chern numbers for the whole manifold in a many-body formulation and show that, related to the aforementioned quantum phase transitions, a topological transition results in a change of the value and sign of the Chern number. We provide both an intuitive and conceptual explanation and argue that these properties could be observed in quantum-gas experiments.

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Section: Discussioncontrasting

confidence: 57%

Section: Introductionmentioning

confidence: 99%

Quantum phases and topological properties of interacting fermions in one-dimensional superlattices

et al. 2019

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“…Following Ref. [30], we study the charge pumping for finite systems with open-boundary conditions by monitoring the polarization P(τ ) of the model (1). The total transferred charge is given by…”

Section: B Pair Pumpingmentioning

confidence: 99%

“…This concept was first introduced by Thouless [25] and may be studied by the generalization of the SSH to the Rice-Mele (RM) model [26]. Recently, with the observation of charge pumping in cold-atom experiments [4][5][6][7], the fate of Thouless pumping in interacting systems, such as the interacting fermionic or bosonic RM model, has attracted a great deal of interest [27][28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Topological charge pumping of bound bosonic pairs

2020

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Experiments with bosonic atoms in optical superlattices allow for the interesting possibility to study the adiabatic quantized pumping of bosonic atoms in the presence of interactions. We investigate this exotic phenomenon for bound bosonic pairs in the paradigmatic Su-Schrieffer-Heeger model where the ground state exhibits topological properties due to dimerized hoppings. We show that at unit filling there exist crossovers and phase transitions to bond-order phases of paired bosons known as the pair-bond-order phase for attractive interactions. The pair-bond-order phase is found to exhibit effective topological properties such as the presence of polarized paired edge states. This is further analyzed by studying the emergence and breakdown of the Thouless charge pumping of bound bosonic pairs by a parametric extension to the famous Rice-Mele model. Finally, we discuss how the pumping of paired bosons or different regimes of breakdown of charge pumping can be probed by state-of-the-art experiments, for example, with repulsively bound bosons.

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“…We expect that this difference originates from the interference effect of the upper band, which is determined by the difference between the lower and upper band instantaneous energy spectrums and the Stokes phase as Eq. (11). Furthermore, it is interesting to compare ∆P (T ), which was introduced in the previous section, with the total pumped charge Q sys of the system.…”

Section: Estimation Of the Lz Formulationmentioning

confidence: 99%

Non-adiabatic extension of the Zak phase and charge pumping in the Rice–Mele model

Kuno

2019

Eur. Phys. J. B

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In this study, the Landau-Zener (LZ) transition method is applied to investigate a weak nonadiabatic effect on the Zak phase and the topological charge pumping in the Rice-Mele model. The nonadiabatic effect is formulated using the LZ transfer matrix. The effective lower band wave function picks up the Stokes phase as well as the usual dynamical phase through two avoided crossings appearing in the two band instantaneous energy spectrum. The interference effect from the upper band has a decisive influence on the decay behavior of the lower band population. A non-adiabatic extension of the Zak phase can then be formulated, corresponding to the center of mass of the lower band Wannier function. Furthermore, we estimate the validity of the LZ formalism and verify the breakdown of the quantization of the topological charge pumping by changing the sweeping speed.

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Breakdown of topological Thouless pumping in the strongly interacting regime

Cited by 49 publications

References 87 publications

Quantum phases and topological properties of interacting fermions in one-dimensional superlattices

Quantum phases and topological properties of interacting fermions in one-dimensional superlattices

Topological charge pumping of bound bosonic pairs

Non-adiabatic extension of the Zak phase and charge pumping in the Rice–Mele model

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