English
Related papers

Related papers: Probing quantum coherence in qubit arrays

200 papers

Quantum gates (unitary gates) on physical systems are usually implemented by controlling the Hamiltonian dynamics. When full descriptions of the Hamiltonians parameters is available, the set of implementable quantum gates is easily…

Quantum Physics · Physics 2019-10-16 Ryosuke Sakai , Akihito Soeda , Mio Murao , Daniel Burgarth

We study the phase space of periodically modulated gravitational cavity by means of quantum recurrence phenomena. We report that the quantum recurrences serve as a tool to connect phase space of the driven system with spectrum in quantum…

Quantum Physics · Physics 2009-11-06 Farhan Saif

We build upon recent work on using Machine Learning models to estimate Hamiltonian parameters using continuous weak measurement of qubits as input. We consider two settings for the training of our model: (1) supervised learning where the…

Quantum Physics · Physics 2025-02-17 Kris Tucker , Amit Kiran Rege , Conor Smith , Claire Monteleoni , Tameem Albash

The process of measuring a two-level quantum system was examined by applying Hamiltonian formalism. For the measurement of an observable that does not commute with the system Hamiltonian, a non-trivial relationship among the strength of…

Quantum Physics · Physics 2011-05-24 Takayuki Miyadera

We show how to implement quantum computation on a system with an intrinsic Hamiltonian by controlling a limited subset of spins. Our primary result is an efficient control sequence on a nearest-neighbor XY spin chain through control of a…

Quantum Physics · Physics 2010-01-27 Alastair Kay , Peter J. Pemberton-Ross

Simulating a system of two driven coupled qubits, we show that the time-averaged probability to find one driven qubit in its ground or excited state can be controlled by an ac drive in the second qubit. Moreover, off-diagonal elements of…

Quantum Physics · Physics 2015-06-11 S. E. Savel'ev , Z. Washington , A. M. Zagoskin , M. J. Everitt

Decoherence, resulting from unwanted interaction between a qubit and its environment, poses a serious challenge towards the development of quantum technologies. Recently, researchers have started analysing how real-time Hamiltonian learning…

Quantum Physics · Physics 2020-06-24 Eleanor Scerri , Erik M. Gauger , Cristian Bonato

Realizing controlled operations is fundamental to the design and execution of quantum algorithms. In quantum simulation and learning of quantum many-body systems, an important subroutine consists of implementing a controlled Hamiltonian…

Quantum Physics · Physics 2025-03-11 Anirban Chowdhury , Ewout van den Berg , Pawel Wocjan

Quantum coherence, rooted in the superposition principle of quantum mechanics, is a crucial quantum resource. Various measures, operational interpretations, and generalizations of quantum coherence have been proposed. In recent years, its…

Quantum Physics · Physics 2025-04-22 Hai Wang , Ujjwal Sen

We theoretically investigate excitation dynamics in one-dimensional arrays of quantum emitters coupled to a waveguide, focusing on localization and long-time population trapping. By combining time-domain simulations with spectral analysis…

Quantum Physics · Physics 2025-11-05 C. -Y. Lee , K. -T. Lin , G. -D. Lin , H. H. Jen

Quantum coherence is one of the primary non-classical features of quantum systems. While protocols such as the Leggett-Garg inequality (LGI) and quantum tomography can be used to test for the existence of quantum coherence and dynamics in a…

Quantum Physics · Physics 2012-12-04 Che-Ming Li , Neill Lambert , Yueh-Nan Chen , Guang-Yin Chen , Franco Nori

We investigate how the time dependence of the Hamiltonian determines the occurrence of Dynamical Localization (DL) in driven quantum systems with two incommensurate frequencies. If both frequencies are associated to impulsive terms, DL is…

Chaotic Dynamics · Physics 2009-11-07 G. Abal , R. Donangelo , A. Romanelli , A. C. Sicardi Schifino , R. Siri

The quantum coherence of a multipartite system is investigated when some of the parties are moving with uniform acceleration and the analysis is carried out using the single mode approximation. Due to acceleration the quantum coherence is…

Long-lived coherences, emerging under periodic pulse driving in the disordered ensembles of strongly interacting spins, offer immense advantages for future quantum technologies, but the physical origin and the key properties of this…

Quantum Physics · Physics 2021-07-13 Walter Hahn , V. V. Dobrovitski

Quantum coherence quantifies the amount of superposition in a quantum system, and is the reason and resource behind several phenomena and technologies. It depends on the natural basis in which the quantum state of the system is expressed,…

Quantum Physics · Physics 2021-08-13 Ingita Banerjee , Kornikar Sen , Chirag Srivastava , Ujjwal Sen

Quantum information processing often uses systems with dipolar interactions. We use a nuclear spin-based quantum simulator, to study the spreading of information in such a dipolar-coupled system and how perturbations to the dipolar…

Quantum Physics · Physics 2014-12-31 Gonzalo A. Alvarez , Robin Kaiser , Dieter Suter

We consider a quantum system that is being continuously monitored, giving rise to a measurement signal. From such a stream of data, information needs to be inferred about the underlying system's dynamics. Here we focus on hypothesis testing…

Quantum Physics · Physics 2024-03-27 Giulio Gasbarri , Matias Bilkis , Elisabet Roda-Salichs , John Calsamiglia

Recently, the basic concept of quantum coherence (or superposition) has gained a lot of renewed attention, after Baumgratz et al. [PRL 113:140401 (2014)], following \AA{}berg [arXiv:quant-ph/0612146], have proposed a resource theoretic…

Quantum Physics · Physics 2017-08-01 Tanmoy Biswas , María García Díaz , Andreas Winter

Quantum coherence is a fundamental characteristic to distinguish quantum systems from their classical counterparts. Though quantum coherence persists in isolated non-interacting systems, interactions inevitably lead to decoherence, which is…

Quantum Gases · Physics 2017-11-15 Ke-Ji Chen , Ho Kwan Lau , Hon Ming Chan , Dajun Wang , Qi Zhou

We propose a new driving scheme, when different parts of a system are driven with different, generally incommensurate, frequencies. Such driving provides a flexible handle to control various properties of the system and to obtain new types…

Optics · Physics 2018-03-01 Huanan Li , Tsampikos Kottos , Boris Shapiro