Non-Hermitian squeezed polarons

Qin, Fang; Shen, Ruizhe; Lee, Ching Hua

doi:10.1103/physreva.107.l010202

Cited by 20 publications

(4 citation statements)

References 159 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also note that non-unitary operators also describe the time evolution of effectively non-Hermitian systems. As such, with some modifications, our algorithm can be adapted to simulate non-Hermitian many-body phenomena as well as entanglement dynamics on the quantum computer [99][100][101][102][103][104][105][106][107][108][109][110][111]. As a concrete case in point, the phase transition associated with PT symmetry breaking is generally induced by gain or loss, which can be realized by coupling system qubits to an ancilla qubit analogously to our approach [112][113][114].…”

Section: Discussionmentioning

confidence: 99%

High-fidelity realization of the AKLT state on a NISQ-era quantum processor

Chen,

Shen,

Lee

et al. 2023

SciPost Phys.

Self Cite

View full text Add to dashboard Cite

The AKLT state is the ground state of an isotropic quantum Heisenberg spin-1 model. It exhibits an excitation gap and an exponentially decaying correlation function, with fractionalized excitations at its boundaries. So far, the one-dimensional AKLT model has only been experimentally realized with trapped-ions as well as photonic systems. In this work, we successfully prepared the AKLT state on a noisy intermediate-scale quantum (NISQ) era quantum device. In particular, we developed a non-deterministic algorithm on the IBM quantum processor, where the non-unitary operator necessary for the AKLT state preparation is embedded in a unitary operator with an additional ancilla qubit for each pair of auxiliary spin-1/2’s. Such a unitary operator is effectively represented by a parametrized circuit composed of single-qubit and nearest-neighbor CX gates. Compared with the conventional operator decomposition method from Qiskit, our approach results in a much shallower circuit depth with only nearest-neighbor gates, while maintaining a fidelity in excess of 99.99% with the original operator. By simultaneously post-selecting each ancilla qubit such that it belongs to the subspace of spin-up |↑>, an AKLT state can be systematically obtained by evolving from an initial trivial product state of singlets plus ancilla qubits in spin-up on a quantum computer, and it is subsequently recorded by performing measurements on all the other physical qubits. We show how the accuracy of our implementation can be further improved on the IBM quantum processor with readout error mitigation.

show abstract

Section: Discussionmentioning

confidence: 99%

High-fidelity realization of the AKLT state on a NISQ-era quantum processor

Chen,

Shen,

Lee

et al. 2023

SciPost Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…These are interesting directions for future research, as they could provide a more complete understanding of the transport properties of impurities in topological systems. Nonhermitian problems can also originate from certain defects [54,55], and different boundary conditions can be used to tune [56] the EP's and realize them in quantum circuits, maybe if we map effective spin models to Wilson chains, then we might look at these phases. Localization in the Hatano-nelson type of models can have dramatic consequences of impurities [57].…”

Section: Discussionmentioning

confidence: 99%

Anderson Impurities In Edge States with Nonlinear Dispersion

M.¹

2023

Preprint

View full text Add to dashboard Cite

A non-linear dispersion can significantly impact the Kondo problem, resulting in anomalous effects on electronic transport. By analyzing a special bath with a θ = π 3 symmetry rotation in the Brillouin zone or 3-fold symmetry in momentum, we derive an effective spin-spin interacting model. Combining the anisotropic Dzyaloshinskii-Moriya (DM) interaction with non-linear dispersion can lead to exceptional points (Ep) in a Hermitian model. Our RG analysis reveals that the spin relaxation time has the signature of coalescence in momentum-resolved couplings and an ideal logarithmic divergence in resistivity over a range of nonlinearity (β). The effective model at the impurity subspace has a Lie group structure of Dirac matrices. We show nontrivial renormalization within a Poorman approximation with the inclusion of potential scattering, and the invariant obtained will not be altered by potential scattering. We expand the model to a two-impurity Kondo model and investigate the Kondo destruction and anomalous spin transport signature by calculating the spin-relaxation time (τ ).Analysis of RG equations zeros and poles show a "Sign Reversion"(SR) regime exists for a Hermitian problem with a critical value of nonlinear coupling J k 3 . Our results show the existence of an out-of-phase RKKY oscillation above and below the critical value of the chemical potential.

show abstract

“…This CoM momentum dependent interaction (CoMMDI) is novel because for almost all natural systems the two-body interactions are independent of the CoM momentum. Further research shows various phenomena, such as Fulde-Ferrell superfluids and synthesis of majorana mass terms, may be realized via ultracold gases with this interaction [18][19][20][21][22][23]. Nevertheless, so far the studies are mainly focused on the many-body effects induced by atomic scattering, and the bound states of this system have not been studied systemically.…”

Section: Introductionmentioning

confidence: 99%

Two-component dimers of ultracold atoms with center-of-mass-momentum dependent interactions

Liu,

Yang,

Zhang

2024

Commun. Theor. Phys.

View full text Add to dashboard Cite

In a previous work [Phys. Rev. A 95, 060701(R) (2017)] we show that a new type of twobody interaction, which depends on the center of mass (CoM) momentum, can be realized forultracold atoms via laser-modulated magnetic Feshbach resonance (MFR). Further studies (e.g., L.He et. al., Phys. Rev. Lett. 120, 045302 (2018)) show that various interesting phenomena, suchas Fulde-Ferrell superfluids, can be induced by the scattering between ultracold atoms with thisinteraction. In this work we investigate the shallow bound states of two ultracold atoms with thistype of interaction. We show that when the magnetic field B is below the MFR point B0, twoshallow bound states can appear in this system. Namely, a “two-component dimer” or a dimerwith pseudo-spin 1/2 can be formed by two atoms. Furthermore, the dispersion curve of the dimermay has either single or double minimums in the CoM momentum space. The latter case canbe explained as a result from significant pseudo-spin-orbital coupling (SOC) effects. Our resultsshow that the ultracold gases with CoM momentum dependent interaction may be a candidate forquantum simulations with ultracold two-component molecules, especially the molecule gases withSOC.

show abstract

Non-Hermitian squeezed polarons

Cited by 20 publications

References 159 publications

High-fidelity realization of the AKLT state on a NISQ-era quantum processor

High-fidelity realization of the AKLT state on a NISQ-era quantum processor

Anderson Impurities In Edge States with Nonlinear Dispersion

Two-component dimers of ultracold atoms with center-of-mass-momentum dependent interactions

Contact Info

Product

Resources

About