Effects of reservoir squeezing on trace-distance correlations and emergence of the pointer basis

Abdul Basit, Hamad Ali, Peng-Bo Li, and Gao Xianlong

Phys. Rev. A 107, 042432 – Published 27 April 2023

Abstract

We investigate theoretically the dynamics of 1-norm geometric quantum correlations and their classical counterparts in a two-qubit system. Both qubits are initially prepared in Bell-diagonal states and locally coupled to separated thermal squeezed baths or a common squeezed thermal bath via energy-preserving interactions. We then unveil the effects of reservoir squeezing on the abrupt changes in the evolution of geometric correlations. It is found that adequately tuning the squeezing phase can efficiently suppress the dephasing rate and delay the appearance of sudden transitions in geometric correlations. Further, we show that the squeezing phase of the bath renders a different avenue to enhance the finite time interval for frozen quantum correlation. On the other hand, in this context, we show that the squeezing strength of the reservoir exhibits a negative role. In addition, in the common bath case, we observe the steady-state correlations and decoherence-free subspace, which can be governed via squeezing parameters. Moreover, the abrupt change from a decaying regime to a constant nonzero value in classical correlation signals the emergence of a pointer-state basis. We show that the emergence of a pointer-state basis can be delayed by suitably adjusting the bath squeezing parameters. Remarkably, we find the optimal value of the squeezing phase, which introduces maximum retardation in the appearance of a pointer-state basis.

Received 18 August 2022
Revised 6 March 2023
Accepted 14 April 2023

DOI:https://doi.org/10.1103/PhysRevA.107.042432

Physics Subject Headings (PhySH)

Quantum control Quantum correlations in quantum information Quantum discord Quantum engineering

Quantum Information, Science & Technology

Authors & Affiliations

Abdul Basit ^1,*, Hamad Ali^2,†, Peng-Bo Li², and Gao Xianlong ^1,‡

¹Department of Physics, Zhejiang Normal University, Jinhua 321004, China
²Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China

^*abasitphy@gmail.com
^†hamad_phy@xjtu.edu.cn
^‡gaoxl@zjnu.edu.cn

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 107, Iss. 4 — April 2023

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
Time evolution of quantum $Q_{G} [ρ_{L B} (t)]$ (blue curves) and classical $C_{G} [ρ_{L B} (t)]$ (red curves) correlations of two qubits locally subjected to thermal baths at zero temperature with different values of the phase difference: (a) $δ θ = 0$ , (b) $δ θ = \frac{π}{4}$ , and (c) $δ θ = \frac{π}{2}$ . In all cases we consider initial correlation parameters $c_{1} = 1$ , $c_{2} = - 0.6$ , $c_{3} = 0.3$ , squeezing strength $r = 0.5$ , and coupling constant $γ = 0.5$ . The insets in each panel show the dynamics of the correlation parameters for different values of $δ θ$ . In each panel the gray vertical solid line manifests the time instant $τ_{E}$ for the emergence of the pointer-state basis.
Reuse & Permissions
Figure 2
Time evolution of quantum $Q_{G} [ρ_{C B} (t)]$ (blue curves) and classical $C_{G} [ρ_{C B} (t)]$ (red curves) correlations of two qubits subjected to a common thermal bath at zero temperature with different values of the phase difference: (a) $δ θ = 0$ , (b) $δ θ = \frac{π}{4}$ , and (c) $δ θ = \frac{π}{2}$ . In all cases we consider initial correlation parameters $c_{1} = 1$ , $c_{2} = - 0.6$ , $c_{3} = 0.3$ , squeezing strength $r = 0.5$ , and coupling constant $γ = 0.5$ . The insets in each panel show the dynamics of the correlation parameters for different values of $δ θ$ . In each panel the gray vertical solid line manifests the time instant $τ_{E}$ for the emergence of the pointer-state basis.
Reuse & Permissions
Figure 3
Time evolution of quantum $Q_{G} [ρ_{L B} (t)]$ (blue curves) and classical $C_{G} [ρ_{L B} (t)]$ (red curves) correlations of two qubits locally subjected to thermal baths at zero temperature with different values of the squeezing strength: (a) $r = 0.1$ , (b) $r = 0.6$ , and (c) $r = 1$ . In all cases we consider initial correlation parameters $c_{1} = 1$ , $c_{2} = - 0.6$ , $c_{3} = 0.3$ , $δ θ = \frac{π}{2}$ , and coupling constant $γ = 0.5$ . The insets in each panel show the dynamics of the correlation parameters for different values of $r$ . In each panel the gray vertical solid line manifests the time instant $τ_{E}$ for the emergence of the pointer-state basis.
Reuse & Permissions
Figure 4
Time evolution of quantum $Q_{G} [ρ_{C B} (t)]$ (blue curves) and classical $C_{G} [ρ_{C B} (t)]$ (red curves) correlations of two qubits subjected to a common thermal thermal bath at zero temperature with different values of the squeezing strength: (a) $r = 0.1$ , (b) $r = 0.6$ , and (c) $r = 1$ . In all cases we consider initial correlation parameters $c_{1} = 1$ , $c_{2} = - 0.6$ , $c_{3} = 0.3$ , $δ θ = \frac{π}{2}$ , and coupling constant $γ = 0.5$ . The insets in each panel show the dynamics of the correlation parameters for different values of $r$ . In each panel the gray vertical solid line manifests the time instant $τ_{E}$ for the emergence of the pointer-state basis.
Reuse & Permissions

Physical Review A

covering atomic, molecular, and optical physics and quantum information