Article
Optics
Salvatore Savasta, Omar Di Stefano, Alessio Settineri, David Zueco, Stephen Hughes, Franco Nori
Summary: This study introduces a modified quantum Rabi model that can provide gauge-invariant physical results in any interaction regime. To achieve this, the implementation of the gauge principle in two-state systems was adopted.
Article
Optics
M. S. Soares, N. F. Svaiter, G. Menezes
Summary: In this paper, we propose an alternative form of the quantum master equation in the theory of open quantum systems. This alternative formalism allows the description of the dynamics of two-level systems moving along different hyperbolic trajectories with distinct proper times. In the Born-Markov approximation, we consider the coupling between a quantum massless scalar field and two-level systems. We demonstrate the emergence of entanglement harvesting from a separable state and verify the phenomenon of entanglement sudden death for different proper accelerations.
Article
Mathematics, Interdisciplinary Applications
Dongmei Li, Yingying Gui, Jinwang Liu, Man Wu
Summary: This paper investigates the equivalence problems of several classes of bivariate polynomial matrices and obtains new results on their equivalence, which are useful for reducing two-dimensional systems.
Article
Optics
Hai-Ning Wu, Cheng Zhang, Jie Song, Yan Xia, Zhi-Cheng Shi
Summary: In this work, we propose an approach for constructing optimal composite pulse sequences to achieve robust population transfer in two-level systems. This approach is applicable to various systems and utilizes a homemade cost function to obtain modulation parameters of composite pulses, rather than nullifying error coefficients. By adjusting the constraints of the cost function, this approach can be extended to achieve arbitrary population transfer. Numerical results demonstrate that the optimized sequences are immune to systematic errors and allow for a broad excitation range of the transition probability. Therefore, this work provides an optimal robust design for controlling quantum states in error-prone environments.
Article
Physics, Mathematical
Pieter Naaijkens, Yoshiko Ogata
Summary: The paper discusses the relationship between entanglement and split property in quantum spin systems, demonstrating how the failure of split property in certain models leads to the existence of anyons. It proves that long-range entanglement is a necessary condition for non-trivial superselection sectors, while states with the split property do not admit non-trivial sectors.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Optics
K. Raimundo, M. C. Baldiotti, R. Fresneda, C. Molina
Summary: In this work, a classical-quantum correspondence for two-level pseudo-Hermitian systems is proposed and analyzed. The presence of a complex external field is described by a pseudo-Hermitian Hamiltonian through a suitable canonical transformation. A covariant quantization scheme is constructed to map canonically related pseudoclassical theories to unitarily equivalent quantum realizations, maintaining a unique metric-inducing isometry between distinct Hilbert spaces.
Article
Optics
T. Z. Luan, H. Z. Shen, X. X. Yi
Summary: This paper proposes a shortcuts to adiabaticity technique based on a transitionless quantum driving algorithm to realize high-fidelity population transfer for general non-Hermitian systems. The method is applicable to systems with strong non-Hermiticity without the rotating wave approximation.
Article
Physics, Multidisciplinary
Chao Zheng
Summary: Non-Hermitian (NH) quantum theory has attracted research interest and in this study, we generalize pseudo-Hermitian systems to their complex counterparts, called pseudo-Hermitian-phi-symmetric systems. We mainly focus on simulating this novel system in a Hermitian system using quantum simulation methods.
Article
Materials Science, Multidisciplinary
Jie Wen, Yuanhao Shi, Jianfang Jia, Jianchao Zeng
Summary: This paper investigates the exponential stabilization of eigenstates for two-level quantum systems based on continuous noise-assisted feedback control. A strategy is proposed to overcome convergence obstacles and allow quantum systems to converge to target eigenstates exponentially. Numerical simulations help verify the effectiveness of noise-assisted feedback control and study the impacts of physical and control parameters on convergence rates.
RESULTS IN PHYSICS
(2021)
Article
Physics, Multidisciplinary
Yuebing Zhou, Jiawei Hu, Hongwei Yu
Summary: In certain cases, using a bath of massive scalar fields as the environment can significantly enlarge the region where entanglement can be generated and slow down the decay rate of entanglement. This allows entanglement to be maintained for a long time over long distances.
Article
Physics, Multidisciplinary
Andreas Ask, Goran Johansson
Summary: The paper investigates the steady state behavior of an open quantum system in a non-Markovian environment. By studying a driven two-level system in a semi-infinite waveguide, it is found that non-Markovian states exhibit exotic behaviors such as population inversion and steady-state coherence beyond what is possible in the Markovian regime.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Benjamin Knorr, Chris Ripken
Summary: Affine gravity is a connection-based formulation of gravity that differs from metric quantum gravity and is classically equivalent to general relativity.
Article
Optics
Julian Huber, Ana Maria Rey, Peter Rabl
Summary: This paper presents an efficient numerical method for simulating the dynamics of interacting spin ensembles in the presence of dephasing and decay. The method combines mean-field dynamics with a Monte Carlo sampling to account for quantum correlations, and can be applied to a variety of experiments in quantum optics or solid-state spin ensembles.
Article
Physics, Applied
Xinyuan You, Ziwen Huang, Ugur Alyanak, Alexander Romanenko, Anna Grassellino, Shaojiang Zhu
Summary: This paper proposes a method to alleviate the limited coherence times in superconducting circuits by designing the noise spectral densities of quantum bits. Specifically, by depolarizing and dephasing the material defects, the high-frequency noise spectrum is smoothed and the low-frequency noise amplitude is suppressed, resulting in a stabilized qubit lifetime and an increased qubit pure dephasing time.
PHYSICAL REVIEW APPLIED
(2022)
Review
Physics, Multidisciplinary
Kaitlin N. Smith, Gokul Subramanian Ravi, Thomas Alexander, Nicholas T. Bronn, Andre R. R. Carvalho, Alba Cervera-Lierta, Frederic T. Chong, Jerry M. Chow, Michael Cubeddu, Akel Hashim, Liang Jiang, Olivia Lanes, Matthew J. Otten, David Schuster, Pranav Gokhale, Nathan Earnest, Alexey Galda
Summary: Quantum information processing offers great potential and promises accelerated problem-solving and innovative opportunities across various fields. To fully harness the power of quantum computing, improving hardware, algorithms, and device-level quantum control is crucial. The Pulse-level Quantum Control Workshop provided a summary of key topics for the quantum community.
FRONTIERS IN PHYSICS
(2022)
Review
Physics, Multidisciplinary
Liu Fei, Ouyang Zhong-Can
Article
Physics, Multidisciplinary
Liu Fei, Xie Hong-Cheng, Lu Zhi-Yue
COMMUNICATIONS IN THEORETICAL PHYSICS
(2014)
Article
Physics, Fluids & Plasmas
Fei Liu
Article
Physics, Multidisciplinary
Fei Liu
COMMUNICATIONS IN THEORETICAL PHYSICS
(2020)
Article
Physics, Multidisciplinary
Fei Liu
Summary: A tilted Liouville-master equation in Hilbert space is proposed for Markovian open quantum systems, serving as an unraveling of the tilted quantum master equation widely used in analyzing and calculating stochastic thermodynamic quantities in quantum stochastic thermodynamics.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2021)
Article
Physics, Multidisciplinary
Fei Liu
Summary: In this study, a kinetic uncertainty relation (KUR) is derived based on Markovian piecewise deterministic processes (PDPs) and applied to open quantum systems. The stationary distributions of classical PDPs are explicitly constructed, and a tilting method is used to derive a rate functional of large deviations. By extending classical results to quantum systems, the KUR is recovered using an improved approximation scheme.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Fei Liu
Summary: By using the age-structure formalism, this paper establishes connections between semi-Markov processes and the dynamics of open quantum systems that satisfy the Markov quantum master equations. It also proposes a generalized Feynman-Kac formula for the semi-Markov processes. The semi-Markov processes inherit all statistical properties possessed by the piecewise deterministic processes of wave functions and show unique advantages in quantum counting statistics, allowing for application to more general counting quantities.
Article
Physics, Fluids & Plasmas
Fei Liu
Summary: By using the probability formulas of quantum trajectories, an auxiliary open quantum system is constructed for a periodically driven open quantum system. It is found that, at a long time limit, the coherent dynamics of the auxiliary system remains the same as that of the original system despite modifications to the Lindblad operators. The construction is illustrated using a periodically driven two-level quantum system.
Article
Physics, Fluids & Plasmas
Ke Cheng, Jia-Qi Dong, Wen-Hui Han, Fei Liu, Liang Huang
Article
Physics, Fluids & Plasmas
Fei Liu, Shanhe Su
Article
Physics, Fluids & Plasmas
Yixiao Qian, Fei Liu
Article
Physics, Fluids & Plasmas
Zhaoyu Fei, H. T. Quan, Fei Liu
Article
Physics, Fluids & Plasmas
Fei Liu, Jingyi Xi
Article
Physics, Fluids & Plasmas
Fei Liu
