Advances in Quantum Information

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Physics".

Deadline for manuscript submissions: closed (31 December 2023) | Viewed by 15222

Special Issue Editors


E-Mail Website
Guest Editor
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Interests: atomic and molecular physics and quantum optics theory; theory of quantum information and quantum computation; condensed matter theory
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
School of Physics, Henan Normal University, Xinxiang 453007, China
Interests: quantum optics; quantum many-body theory; quantum information; non-Hermitian quantum mechanics

Special Issue Information

Dear Colleagues,

Quantum information theory is a hot contemporary topic in physical science. Quantum information theory brings together ideas from classical information theory, quantum mechanics and computer science. Quantum information harnesses the power of quantum mechanics and brings a radical new era of technology. Symmetry phenomena play a very important role in quantum science, such as in classic PT symmetry.

This Special Issue invites contributions reporting on developments related to the theory and applications of quantum information, quantum mechanics, quantum transport, quantum chaos, quantum Hall effect systems, quantum phase transitions, etc. Moreover, contributions should fall within the scope of the journal Symmetry.

Submit your paper and select the Journal “Symmetry” and the Special Issue “Advances in Quantum Information” via: MDPI submission system. Our papers will be published on a rolling basis and we will be pleased to receive your submission once you have finished it.

Prof. Dr. Wu-Ming Liu
Dr. Xingdong Zhao
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Symmetry is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • quantum information
  • quantum mechanics
  • quantum transport
  • quantum chaos
  • quantum Hall effect systems
  • quantum phase transition

Published Papers (9 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

13 pages, 560 KiB  
Article
Phonon Blockade in Parametrically Pumped Acoustic Cavity at Finite Temperature
by Zhenglu Duan, Yongkang Shao, Yi Ren and Biao Huang
Symmetry 2023, 15(1), 245; https://doi.org/10.3390/sym15010245 - 16 Jan 2023
Viewed by 1093
Abstract
In this study, we investigated the phonon blockade effect in a parametrically driven and dissipative acoustic cavity at finite temperature. With the approximated analytical results based on the steady-state density-matrix master equation, we found that a quantum-interference-induced phonon blockade exists at finite temperature. [...] Read more.
In this study, we investigated the phonon blockade effect in a parametrically driven and dissipative acoustic cavity at finite temperature. With the approximated analytical results based on the steady-state density-matrix master equation, we found that a quantum-interference-induced phonon blockade exists at finite temperature. We found a crossover between the quantum and thermal regimes on the curve of the second-order correlation function of the acoustic mode as the temperature increases. This phenomenon implies an asymmetry about the quantum and classic regimes. We also numerically simulated the single-phonon emission using the Monte Carlo wave function method. The results showed that a wide and deep dip around the zero time delay exists on the curve of the time-delayed second-order correlation function, which implies the possibility of observing a strong phonon blockade with pulse driving. Our study outlines a potential candidate for a efficient single-phonon source and applications in quantum information and phononic quantum networks. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

9 pages, 850 KiB  
Article
Dynamical Stability in a Non-Hermitian Kicked Rotor Model
by Wenlei Zhao and Huiqian Zhang
Symmetry 2023, 15(1), 113; https://doi.org/10.3390/sym15010113 - 31 Dec 2022
Cited by 1 | Viewed by 1139
Abstract
We investigate the quantum irreversibility and quantum diffusion in a non-Hermitian kicked rotor model for which the kicking strength is complex. Our results show that the exponential decay of Loschmidt echo gradually disappears with increasing the strength of the imaginary part of non-Hermitian [...] Read more.
We investigate the quantum irreversibility and quantum diffusion in a non-Hermitian kicked rotor model for which the kicking strength is complex. Our results show that the exponential decay of Loschmidt echo gradually disappears with increasing the strength of the imaginary part of non-Hermitian driven potential, demonstrating the suppress of the exponential instability by non-Hermiticity. The quantum diffusion exhibits the dynamical localization in momentum space, namely, the mean square of momentum increases to saturation with time evolution, which decreases with the increase of the strength of the imaginary part of the kicking. This clearly reveals the enhancement of dynamical localization by non-Hermiticity. We find, both analytically and numerically, that the quantum state are mainly populated on a very few quasieigenstates with significantly large value of the imaginary part of quasienergies. Interestingly, the average value of the inverse participation ratio of quasieigenstates decreases with the increase of the strength of the imaginary part of the kicking potential, which implies that the feature of quasieigenstates determines the stability of wavepacket’s dynamics and the dynamical localization of energy diffusion. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

14 pages, 2578 KiB  
Article
Quantum Speed-Up Induced by the Quantum Phase Transition in a Nonlinear Dicke Model with Two Impurity Qubits
by Wangjun Lu, Cuilu Zhai, Yan Liu, Yaju Song, Jibing Yuan, Songsong Li and Shiqing Tang
Symmetry 2022, 14(12), 2653; https://doi.org/10.3390/sym14122653 - 15 Dec 2022
Cited by 1 | Viewed by 1364
Abstract
In this paper, we investigate the effect of the Dicke quantum phase transition on the speed of evolution of the system dynamics. At the phase transition point, the symmetry associated with the system parity operator begins to break down. By comparing the magnitudes [...] Read more.
In this paper, we investigate the effect of the Dicke quantum phase transition on the speed of evolution of the system dynamics. At the phase transition point, the symmetry associated with the system parity operator begins to break down. By comparing the magnitudes of the two types of quantum speed limit times, we find that the quantum speed limit time of the system is described by one of the quantum speed limit times, whether in the normal or superradiant phase. We find that, in the normal phase, the strength of the coupling between the optical field and the atoms has little effect on the dynamical evolution speed of the system. However, in the superradiant phase, a stronger atom–photon coupling strength can accelerate the system dynamics’ evolution. Finally, we investigate the effect of the entanglement of the initial state of the system on the speed of evolution of the system dynamics. We find that in the normal phase, the entanglement of the initial state of the system has almost no effect on the system dynamics’ evolution speed. However, in the superradiant phase, larger entanglement of the system can accelerate the evolution of the system dynamics. Furthermore, we verify the above conclusions by the actual evolution of the system. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

19 pages, 5698 KiB  
Article
Decoherence Effects in a Three-Level System under Gaussian Process
by Sultan M. Zangi, Atta ur Rahman, Zhao-Xo Ji, Hazrat Ali and Huan-Guo Zhang
Symmetry 2022, 14(12), 2480; https://doi.org/10.3390/sym14122480 - 23 Nov 2022
Cited by 8 | Viewed by 1354
Abstract
When subjected to a classical fluctuating field characterized by a Gaussian process, we examine the purity and coherence protection in a three-level quantum system. This symmetry of the three-level system is examined when the local random field is investigated further in the noiseless [...] Read more.
When subjected to a classical fluctuating field characterized by a Gaussian process, we examine the purity and coherence protection in a three-level quantum system. This symmetry of the three-level system is examined when the local random field is investigated further in the noiseless and noisy regimes. In particular, we consider fractional Gaussian, Gaussian, Ornstein–Uhlenbeck, and power law noisy regimes. We show that the destructive nature of the Ornstein–Uhlenbeck noise toward the symmetry of the qutrit to preserve encoded purity and coherence remains large. Our findings suggest that properly adjusting the noisy parameters to specifically provided values can facilitate optimal extended purity and coherence survival. Non-vanishing terms appear in the final density matrix of the single qutrit system, indicating that it is in a strong coherence regime. Because of all of the Gaussian noises, monotonic decay with no revivals has been observed in the single qutrit system. In terms of coherence and information preservation, we find that the current qutrit system outperforms systems with multiple qubits or qutrits using purity and von Neumann entropy. A comparison of noisy and noiseless situations shows that the fluctuating nature of the local random fields is ultimately lost when influenced using the classical Gaussian noises. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

13 pages, 3297 KiB  
Article
Realization of Quantum Swap Gate and Generation of Entangled Coherent States
by Ziqiu Zhang, Xi Jiang and Shiqing Tang
Symmetry 2022, 14(9), 1951; https://doi.org/10.3390/sym14091951 - 19 Sep 2022
Cited by 2 | Viewed by 1769
Abstract
The cross fusion of quantum mechanics and information science forms quantum information science. Quantum logic gates and quantum entanglement are very important building blocks in quantum information processing. In this paper, we propose one-step schemes for realizing quantum swap gates and generating two-mode [...] Read more.
The cross fusion of quantum mechanics and information science forms quantum information science. Quantum logic gates and quantum entanglement are very important building blocks in quantum information processing. In this paper, we propose one-step schemes for realizing quantum swap gates and generating two-mode entangled coherent states via circuit QED. In our scheme, due to the adiabatic elimination of the excited state of the qutrit under the condition of large detuning, the decoherence of the spontaneous emission of the qutrit can be ignored. The fidelity of the quantum swap gate remains at a very high level. In addition, we also explore the nonclassical properties of two-mode entangled coherent states prepared in our scheme by addressing the second-order correlation function and intermodal squeezing. In particular, two classes of entangled coherent states demonstrate distinct entanglement and nonclassical behavior. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

11 pages, 1168 KiB  
Article
Nonlinear Optical Potential with Parity-Time Symmetry in a Coherent Atomic Gas
by Delvi Antonio Polanco Adames, Jianpeng Dou, Ji Lin, Gengjun Zhu and Huijun Li
Symmetry 2022, 14(6), 1135; https://doi.org/10.3390/sym14061135 - 31 May 2022
Viewed by 1131
Abstract
We propose a scheme to realize a parity-time (PT) symmetric nonlinear system in a coherent atomic gas via electromagnetically induced transparency. We show that it is possible to construct an optical potential with PT symmetry due to the interplay among the [...] Read more.
We propose a scheme to realize a parity-time (PT) symmetric nonlinear system in a coherent atomic gas via electromagnetically induced transparency. We show that it is possible to construct an optical potential with PT symmetry due to the interplay among the Kerr nonlinearity stemmed from the atom-photon interaction, the linear potential induced by a far-detuned Stark laser field, and the optical gain originated from an incoherent pumping. Since the real part of the PT-symmetric potential depends only on the intensity of the probe field, the potential is nonlinear and its PT-symmetric properties are determined by the input laser intensity of the probe field. Moreover, we obtain the fundamental soliton solutions of the system and attain their stability region in the system parameter space. The dependence of the exceptional point (EP) location on the soliton maximum amplitude is also illustrated. The research results reported here open a new avenue for understanding the unique properties of PT symmetry of a nonlinear system. They are also promising for designing novel optical devices applicable in optical information processing and transmission. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

15 pages, 497 KiB  
Article
Temporal Quantum Memory and Non-Locality of Two Trapped Ions under the Effect of the Intrinsic Decoherence: Entropic Uncertainty, Trace Norm Nonlocality and Entanglement
by Abdel-Baset A. Mohamed, Atta Ur Rahman and Hichem Eleuch
Symmetry 2022, 14(4), 648; https://doi.org/10.3390/sym14040648 - 23 Mar 2022
Cited by 14 | Viewed by 1643
Abstract
The engineering properties of trapped ions and their capacity to engender numerous quantum information resources determine many aspects of quantum information processing. We devise a setup of coherent and even coherent fields acting on two trapped ions to generate quantum memory, non-locality, and [...] Read more.
The engineering properties of trapped ions and their capacity to engender numerous quantum information resources determine many aspects of quantum information processing. We devise a setup of coherent and even coherent fields acting on two trapped ions to generate quantum memory, non-locality, and entanglement. Various effects, such as intrinsic decoherence, Lamb–Dicke regime, and dipole–dipole interaction are investigated. The inter-coupling of trapped ions, as well as the generation and dynamics of correlations between them, are analyzed. Using quantum memory assisted entropic uncertainty, trace-norm measurement induced non-locality, and concurrence, we find that the coherent and even coherent fields successfully generate non-local correlations in trapped-ions, with the latter being more resourceful for the dynamics and preservation of the non-local correlations. Furthermore, we observe that the entropic uncertainty and the trace norm induced non-locality present symmetrical dynamics. The dipole–dipole interaction improves correlation’s generation, robustness, and entropic uncertainty suppression. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

11 pages, 767 KiB  
Article
Topological Superconducting Transition Characterized by a Modified Real-Space-Pfaffian Method and Mobility Edges in a One-Dimensional Quasiperiodic Lattice
by Shujie Cheng, Yufei Zhu and Xianlong Gao
Symmetry 2022, 14(2), 371; https://doi.org/10.3390/sym14020371 - 13 Feb 2022
Cited by 1 | Viewed by 1450
Abstract
A modified real-space-Pfaffian method is applied to characterize the topological superconducting transition of a one-dimensional p-wave superconductor with quasiperiodic potentials. We found that the Majorana zero-energy mode exists in the topological non-trivial phase, and its spatial distribution is localized at ends of [...] Read more.
A modified real-space-Pfaffian method is applied to characterize the topological superconducting transition of a one-dimensional p-wave superconductor with quasiperiodic potentials. We found that the Majorana zero-energy mode exists in the topological non-trivial phase, and its spatial distribution is localized at ends of the system, whereas in the topological trivial phase, there is no Majorana zero mode. Furthermore, we numerically found that due to the competition between the localized quasi-disorder and the extended p-wave pairing, there are mobility edges in the energy spectra. Our theoretical work enriches the research on the quasiperiodic p-wave superconducting models. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

Review

Jump to: Research

14 pages, 1983 KiB  
Review
Review of the Applications of Kalman Filtering in Quantum Systems
by Kezhao Ma, Jia Kong, Yihan Wang and Xiao-Ming Lu
Symmetry 2022, 14(12), 2478; https://doi.org/10.3390/sym14122478 - 22 Nov 2022
Cited by 2 | Viewed by 2765
Abstract
State variable and parameter estimations are important for signal sensing and feedback control in both traditional engineering systems and quantum systems. The Kalman filter, which is one of the most popular signal recovery techniques in classical systems for decades, has now been connected [...] Read more.
State variable and parameter estimations are important for signal sensing and feedback control in both traditional engineering systems and quantum systems. The Kalman filter, which is one of the most popular signal recovery techniques in classical systems for decades, has now been connected to the stochastic master equations of linear quantum mechanical systems. Various studies have invested effort on mapping the state evolution of a quantum system into a set of classical filtering equations. However, establishing proper evolution models with symmetry to classical filter equation for quantum systems is not easy. Here, we review works that have successfully built a Kalman filter model for quantum systems and provide an improved method for optimal estimations. We also discuss a practical scenario involving magnetic field estimations in quantum systems, where non-linear Kalman filters could be considered an estimation solution. Full article
(This article belongs to the Special Issue Advances in Quantum Information)
Show Figures

Figure 1

Back to TopTop