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Related papers: Decoherence in Waveguide Quantum Electrodynamics u…

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Waveguides potentially offer an effective medium for interconnecting quantum processors within a modular framework, facilitating the coherent quantum state transfer between the qubits across separate chips. In this work, we analyze a…

The preparation and control of quantum states lie at the heart of quantum information science (QIS). Recent advances in solid-state quantum emitters (QEs) and nanophotonics have transformed the landscape of quantum photonic technologies,…

We present a simple protocol to purify a coherent-state superposition that has undergone a linear lossy channel. The scheme constitutes only a single beam splitter and a homodyne detector, and thus is experimentally feasible. In practice, a…

Reducing decoherence is an essential step toward realizing general-purpose quantum computers beyond the present noisy intermediate-scale quantum (NISQ) computers. To this end, dynamical decoupling (DD) approaches in which external fields…

Quantum Physics · Physics 2022-09-23 Yukiyoshi Ohtsuki , Suicho Mikami , Toru Ajiki , David J. Tannor

Dissipative light-matter coupling plays a vital role in non-Hermitian physics, but it remains largely unexplored in waveguide QED systems. In this work, we find that by employing pseudo-Hermitian symmetry rather than anti-PT symmetry, the…

Quantum Physics · Physics 2025-03-20 Xing-Liang Dong , Peng-Bo Li , Zongping Gong , Franco Nori

Molecular nanomagnets are quantum spin systems potentially serving as qudits for future quantum technologies thanks to their many accessible low-energy states. At low temperatures, the primary source of error in these systems is pure…

Coherent control of individual two-level systems (TLSs) is at the basis of any implementation of quantum information. An impressive level of control is now achieved using nuclear, vacancies and charge spins. Manipulation of bright exciton…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 F. Fras , Q. Mermillod , G. Nogues , C. Hoarau , C. Schneider , M. Kamp , S. Höfling , W. Langbein , J. Kasprzak

Random fluctuations caused by environmental noise can lead to decoherence in quantum systems. Exploring and controlling such dissipative processes is both fundamentally intriguing and essential for harnessing quantum systems to gain…

Understanding the excitation spectrum in two-dimensional quantum many-body systems has long been a challenging task. We present an approach by introducing an excitation ansatz based on an infinite matrix product state (MPS) on a helix…

Strongly Correlated Electrons · Physics 2024-02-26 Xing-Yu Zhang , Runze Chi , Yang Liu , Lei Wang

Coherence is a fundamental characteristic of quantum systems and central to understanding quantum behaviour. It is also important for a variety of applications in quantum information. However, physical systems suffer from decoherence due to…

Superconducting microwave cavities with ultra-high Q-factors are revolutionizing the field of quantum computing, offering long coherence times exceeding 1 ms, which is critical for realizing scalable multi-qubit quantum systems with low…

Quantum Physics · Physics 2023-04-20 Alex Krasnok , Pashupati Dhakal , Arkady Fedorov , Pedro Frigola , Michael Kelly , Sergey Kutsaev

The Lindblad approach to continuous quantum measurements is applied to a system composed of a two-level atom interacting with a stationary quantized electromagnetic field through a dispersive coupling fulfilling quantum nondemolition…

Quantum Physics · Physics 2009-10-31 Roberto Onofrio , Lorenza Viola

Repeated closed-loop control operations acting as piecewise-constant Liouville superoperators conditioned on the outcomes of regularly performed measurements may effectively be described by a fixed-point iteration for the density matrix.…

Quantum Physics · Physics 2012-06-26 Gernot Schaller

We study decoherence processes of an S = 1/2 localized spin coupled to conduction band electrons in a metal or a semiconductor via an Ising-like interaction. We derive master equations for the density matrix of the localized spin, by…

Materials Science · Physics 2009-11-13 Naoyoshi Yamada , Akimasa Sakuma , Hiroki Tsuchiura

The mechanism of decoherence for a quantum system with rotational degrees of freedom is studied. From a simple model of elastic scattering, we show that the non-diagonal density matrix elements of the system exponentially decay. The decay…

Quantum Physics · Physics 2016-11-18 Changchun Zhong , F. Robicheaux

We consider an ensemble of quantum systems whose average evolution is described by a density matrix, solution of a Lindblad-Kossakowski differential equation. We focus on the special case where the decoherence is only due to a highly…

Mathematical Physics · Physics 2008-01-11 Mazyar Mirrahimi , Pierre Rouchon

Coherence properties are central to quantum systems and are at the heart of phenomena such as superconductivity. Here we study coherence properties of an ultracold Bose gas in a two-dimensional optical lattice across the thermal phase…

Quantum Gases · Physics 2024-10-15 Justus C. Brüggenjürgen , Mathis S. Fischer , Christof Weitenberg

We discuss the relaxation and dephasing rates that result from the control and the measurement setup itself in experiments on Josephson persistent-current qubits. For control and measurement of the qubit state, the qubit is inductively…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Caspar H. van der Wal , F. K. Wilhelm , C. J. P. M. Harmans , J. E. Mooij

We study the quantum dynamics of multiple two-level atoms (qubits) in a waveguide quantum electrodynamics system, with a focus on modified superradiance effects between two or four atoms with finite delay times. Using a numerically exact…

Quantum Physics · Physics 2025-06-23 Sofia Arranz Regidor , Franco Nori , Stephen Hughes

We compute the multipartite entanglement measures such as the global entanglement of various one- and two-dimensional quantum systems to probe the quantum criticality based on the matrix and tensor product states (MPSs/TPSs). We use…

Quantum Physics · Physics 2015-07-24 Ching-Yu Huang , Feng-Li Lin
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