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Related papers: Decoherence and dephasing in multilevel systems in…

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Material defects fundamentally limit the coherence times of superconducting qubits, and manufacturing completely defect-free devices is not yet possible. Therefore, understanding the interactions between defects and a qubit in a real…

Most discussions of decoherence in the literature consider the high-temperature regime but it is also known that, in the presence of dissipation, decoherence can occur even at zero temperature. Whereas most previous investigations all…

Quantum Physics · Physics 2009-11-10 G. W. Ford , R. F. O'Connell

The character of evolution of an open quantum system is often encoded in the correlation function of the environment or, equivalently, in the spectral density function of the interaction. When the environment is heterogeneous, e.g. consists…

Quantum Physics · Physics 2021-01-20 V. A. Mikhailov , N. V. Troshkin

Dynamical decoupling as a quantum control strategy aims at suppressing quantum decoherence adopting the popular philosophy that the disorder in the unitary evolution of the open quantum system caused by environmental noises should be…

Quantum Physics · Physics 2018-01-17 Jun Jing , Ting Yu , Chi-Hang Lam , J. Q. You , Lian-Ao Wu

As a model of decohering environment, we show that quantum chaotic system behave equivalently as many-body system. An approximate formula for the time evolution of the reduced density matrix of a system interacting with a quantum chaotic…

Quantum Physics · Physics 2009-04-24 Jayendra N. Bandyopadhyay

By coupling with a qubit, we demonstrate that qubit decoherence can unambiguously detect the occurrence of ground-state degeneracy in many-body systems. We first demonstrate universality using the two-band model. Consequently, several…

Quantum Physics · Physics 2016-12-28 H. T. Cui , X. X. Yi

We present a thorough investigation of the phenomena of frozen and time-invariant quantum discord for two-qubit systems independently interacting with local reservoirs. Our work takes into account several significant effects present in…

Quantum Physics · Physics 2018-03-09 F. T. Tabesh , G. Karpat , S. Maniscalco , S. Salimi , A. S. Khorashad

We theoretically study the quantum speed limits (QSLs) of a qubit system coupled to a thermal dephasing environment with an Ohmic-like spectral density. Based on the geometric QSLs time bound, which is derived by employing the trace…

Quantum Physics · Physics 2025-04-08 Xiangji Cai , Yanyan Feng , Jing Ren , Kang Lan , Shuning Sun , Xiangjia Meng , Artur Czerwinski

We study decoherence effects in qubits coupled to environments that exhibit resonant frequencies in their spectral function. We model the coupling of the qubit to its environment via the Caldeira-Leggett formulation of quantum…

Superconductivity · Physics 2010-06-07 Kaushik Mitra , C. A. R. Sá de Melo

Decoherence originates from the leakage of quantum information into external degrees of freedom. For a qubit the two main decoherence channels are relaxation and dephasing. Here, we report an experiment on a superconducting qubit where we…

Quantum Physics · Physics 2018-07-16 Q. Ficheux , S. Jezouin , Z. Leghtas , B. Huard

Decoherence is strongly influenced by environmental criticality, with conventional Hermitian critical points typically enhancing the loss of quantum coherence. Here, we show that this paradigm is fundamentally altered in non-Hermitian…

Quantum Physics · Physics 2026-02-17 Mei-Lin Li , Zuo Wang , Liang He

In this paper we study the low temperature kinetics of the electrons in the system composed of a quantum dot connected to two leads by solving the equation of motion. The decoherence and the relaxation of the system caused by the gate…

Strongly Correlated Electrons · Physics 2009-11-13 M. Q. Weng

We consider pure dephasing of Bell states of electron spin qubits interacting with a sparse bath of nuclear spins. Using the newly developed two-qubit generalization of cluster correlation expansion method, we calculate the spin echo decay…

Mesoscale and Nanoscale Physics · Physics 2018-10-09 Damian Kwiatkowski , Łukasz Cywiński

We investigate the intricate dynamics of quantum coherence and non-classical correlations in a two-qubit open quantum system coupled to a squeezed thermal reservoir. By exploring the correlations between spatially separated qubits, we…

Quantum Physics · Physics 2026-02-24 Neha Pathania , Ramniwas Meena , Subhashish Banerjee

It is shown that a nonequilibrium environment can be instrumental in suppressing decoherence between distinct decoherence free subspaces in quantum registers. The effect is found in the framework of exact coherent-product solutions for…

Quantum Physics · Physics 2009-11-07 S. Gheorghiu-Svirschevski

Decoherence of a quantum state coupled to an exterior environment is at the foundation of our understanding of the emergence of classical behavior from the quantum world, but how does it emerge in a finite closed quantum system? Here this…

Quantum Physics · Physics 2015-06-16 O. Fialko

We study the use of a pair of qubits as a decoherence probe of a non-trivial environment. This dual-probe configuration is modelled by three two-level-systems which are coupled in a chain in which the middle system represents an…

Quantum Physics · Physics 2012-02-09 Jan Jeske , Jared H. Cole , Clemens Müller , Michael Marthaler , Gerd Schön

The qubit (or a system of two quantum dots) has become a standard paradigm for studying quantum information processes. Our focus is Decoherence due to interaction of the qubit with its environment, leading to noise. We consider quantum…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Ebad Kamil , Sushanta Dattagupta

Quantum sensors and qubits are usually two-level systems (TLS), the quantum analogs of classical bits which assume binary values '0' or '1'. They are useful to the extent to which they can persist in quantum superpositions of '0' and '1' in…

Quantum Physics · Physics 2024-01-19 A. Beckert , M. Grimm , N. Wili , R. Tschaggelar , G. Jeschke , G. Matmon , S. Gerber , M. Müller , G. Aeppli

We investigate the decoherence of a qubit coupled to either a quantum two-level system (TLS) again coupled to an environment, or a classical fluctuator modeled by random telegraph noise. In order to do this we construct a model for the…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Henry J. Wold , Håkon Brox , Yuri M. Galperin , Joakim Bergli