Protection of quantum evolutions under parity-time symmetric non-Hermitian Hamiltonians by dynamical decoupling

• URL: http://arxiv.org/abs/2203.01481v2
• Date: Fri, 1 Apr 2022 12:50:58 GMT
• Title: Protection of quantum evolutions under parity-time symmetric non-Hermitian Hamiltonians by dynamical decoupling
• Authors: Ji Bian, Kunxu Wang, Pengfei Lu, Xinxin Rao, Hao Wu, Qifeng Lao, Teng Liu, Yang Liu, Feng Zhu, Le Luo
• Abstract summary: Parity-time (PT) symmetric non-Hermitian Hamiltonians bring about many novel features and interesting applications. The performance of evolutions under $mathcalPT$-symmetric Hamiltonians is degraded by the inevitable noise and errors. In contrast to Hermitian Hamiltonians, the fluctuations in dissipative beams that are utilized to generate non-Hermitian contributions in the PT-symmetric Hamiltonians cause additional errors. Here we achieve the protection of PT-symmetric Hamiltonians against noise acting along the qubit's quantization axis by combining quantum evolutions with dynamical decoupling sequences
• Score: 8.540612560553887
• License: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Abstract: Parity-time (PT) symmetric non-Hermitian Hamiltonians bring about many novel features and interesting applications such as quantum gates faster than those in Hermitian systems, and topological state transfer. The performance of evolutions under $\mathcal{PT}$-symmetric Hamiltonians is degraded by the inevitable noise and errors due to system-environment interaction and experimental imperfections. In contrast to Hermitian Hamiltonians, the fluctuations in dissipative beams that are utilized to generate non-Hermitian contributions in the PT-symmetric Hamiltonians cause additional errors. Here we achieve the protection of PT-symmetric Hamiltonians against noise acting along the qubit's quantization axis by combining quantum evolutions with dynamical decoupling sequences. We demonstrate the performance of our method by numerical simulations. Realistic noise sources and parameters are chosen including: constant detuning error, time-varying detuning noise and dissipative-beam noise. The fidelities of the protected evolutions are well above the unprotected ones under all the above situations. Our work paves the way for further studies and applications of non-Hermitian $\mathcal{PT}$-symmetric physics in noisy quantum systems.

Related papers

• Quantum Noise Suppression in Non-Hermitian Resonators at Exceptional Point [0.0]
  We investigate the impact of quantum noise on non-Hermitian resonators at an exceptional point (EP) The system's irreversible Markovian dynamics is modeled using the Lindblad master equation. Out of the $mathcalPmathcalT$-symmetric regime, however, the system demonstrates stability within a specific parametric domain.
  arXiv  Detail & Related papers  (2025-01-14T15:13:10Z)
• Non-Markovian Noise in Symmetry-Preserving Quantum Dynamics [0.0]
  We develop a framework for quantifying the impact of non-Markovian noise on symmetric quantum evolution. We demonstrate analytically that symmetry-preserving noise maintains the symmetric subspace, while non-symmetric noise leads to highly conserved specific leakage errors.
  arXiv  Detail & Related papers  (2025-01-11T19:00:05Z)
• The robustness of entanglement in non-Hermitian cavity optomechanical system even away from exceptional points [2.778721019132512]
  Quantum physics can be extended into the complex domain by considering non-Hermitian Hamiltonians that are $mathcalPT$-symmetric. We find that the sudden disappearance of entanglement can be mitigated at EPs (similar to $mathcalPT$-symmetric systems) but also show that the revival of entanglement is quite robust to thermal noise in a group of parameters away from the EPs.
  arXiv  Detail & Related papers  (2024-12-11T06:18:05Z)
• Robust analog quantum simulators by quantum error-detecting codes [22.034646136056804]
  We provide a recipe for error-resilient Hamiltonian simulations, making use of an excited encoding subspace stabilized by solely $2$-local commuting Hamiltonians. Our method is scalable as it only requires penalty terms that scale to system size.
  arXiv  Detail & Related papers  (2024-12-10T18:58:05Z)
• Non-Hermiticity in quantum nonlinear optics through symplectic transformations [0.0]
  We show that second-quantised Hermitian Hamiltonians on the Fock space give rise to non-Hermitian effective Hamiltonians. We create a quantum optical scheme for simulating arbitrary non-unitary processes by way of singular value decomposition.
  arXiv  Detail & Related papers  (2023-10-06T18:41:46Z)
• Symmetric Pruning in Quantum Neural Networks [111.438286016951]
  Quantum neural networks (QNNs) exert the power of modern quantum machines. QNNs with handcraft symmetric ansatzes generally experience better trainability than those with asymmetric ansatzes. We propose the effective quantum neural tangent kernel (EQNTK) to quantify the convergence of QNNs towards the global optima.
  arXiv  Detail & Related papers  (2022-08-30T08:17:55Z)
• Noise-resilient Edge Modes on a Chain of Superconducting Qubits [103.93329374521808]
  Inherent symmetry of a quantum system may protect its otherwise fragile states. We implement the one-dimensional kicked Ising model which exhibits non-local Majorana edge modes (MEMs) with $mathbbZ$ parity symmetry. MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism.
  arXiv  Detail & Related papers  (2022-04-24T22:34:15Z)
• Algebraic Compression of Quantum Circuits for Hamiltonian Evolution [52.77024349608834]
  Unitary evolution under a time dependent Hamiltonian is a key component of simulation on quantum hardware. We present an algorithm that compresses the Trotter steps into a single block of quantum gates. This results in a fixed depth time evolution for certain classes of Hamiltonians.
  arXiv  Detail & Related papers  (2021-08-06T19:38:01Z)
• Non-equilibrium stationary states of quantum non-Hermitian lattice models [68.8204255655161]
  We show how generic non-Hermitian tight-binding lattice models can be realized in an unconditional, quantum-mechanically consistent manner. We focus on the quantum steady states of such models for both fermionic and bosonic systems.
  arXiv  Detail & Related papers  (2021-03-02T18:56:44Z)
• Experimental simulation of the Parity-Time-symmetric dynamics using photonics qubits [7.67529162088556]
  We experimentally demonstrate the general dynamical evolution of a two-level system under the action of PT symmetric Hamiltonian. Our work provides a route for further exploiting the exotic properties of PT symmetric Hamiltonian for quantum simulation and quantum information processing.
  arXiv  Detail & Related papers  (2020-04-19T23:08:11Z)
• Exponentially-enhanced quantum sensing with non-Hermitian lattice dynamics [77.34726150561087]
  We show that certain asymmetric non-Hermitian tight-binding models with a $mathbbZ$ symmetry yield a pronounced sensing advantage. Our setup is directly compatible with a variety of quantum optical and superconducting circuit platforms.
  arXiv  Detail & Related papers  (2020-04-01T17:14:14Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.