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We study the performance of quantum thermal machines in which the working fluid of the model is represented by a many-body quantum system that is periodically connected with external baths via local couplings. A formal characterization of…

Quantum Physics · Physics 2025-05-21 Edoardo Maria Centamori , Michele Campisi , Vittorio Giovannetti

Precision control of quantum systems is the driving force for both quantum technology and the probing of physics at the quantum and nano-scale. We propose an implementation independent method for in situ quantum control that leverages…

Quantum Physics · Physics 2015-07-14 Christopher Ferrie , Osama Moussa

An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective…

Quantum Physics · Physics 2008-10-22 Daoyi Dong , Chenbin Zhang , Herschel Rabitz , Alexander Pechen , Tzyh-Jong Tarn

We review progress on the spintronics proposal for quantum computing where the quantum bits (qubits) are implemented with electron spins. We calculate the exchange interaction of coupled quantum dots and present experiments, where the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hans-Andreas Engel , L. P. Kouwenhoven , Daniel Loss , C. M. Marcus

We propose a quantitative criterion to determine whether the coupled quantum systems can achieve complete synchronization or phase synchronization in the process of analyzing quantum synchronization. Adopting the criterion, we discuss the…

Quantum Physics · Physics 2015-09-14 Wenlin Li , Chong Li , Heshan Song

This paper concerns a class of uncertain linear quantum systems subject to quadratic perturbations in the system Hamiltonian. A small gain approach is used to evaluate the performance of the given quantum system. In order to get improved…

Systems and Control · Computer Science 2015-08-12 Chengdi Xiang , Ian R. Petersen , Daoyi Dong

A major challenge to the control of infinite dimensional quantum systems is the irreversibility which is often present in the system dynamics. Here we consider systems with discrete-spectrum Hamiltonians operating over a Schwartz space…

Quantum Physics · Physics 2014-03-13 Roger S. Bliss , Daniel Burgarth

As quantum control approaches hardware-imposed performance limits, weak effects omitted by reduced models become consequential. Assumptions required for analytic tractability then cease to guide control design and instead constrain further…

The most basic scenario of quantum control involves the organized manipulation of pure dynamical states of the system by means of unitary transformations. Recently, Vilela Mendes and Mank'o have shown that the conditions for controllability…

Quantum Physics · Physics 2009-11-10 A. Mandilara , J. W. Clark

Important properties of a quantum system are not directly measurable, but they can be disclosed by how fast the system changes under controlled perturbations. In particular, asymmetry and entanglement can be verified by reconstructing the…

Invariant-based inverse engineering is an elegant approach to quantum control with corresponding experimental implementations that perform tasks with applications in quantum information processing such as shuttling trapped ions. We build on…

Quantum Physics · Physics 2021-12-30 Selwyn Simsek , Florian Mintert

For spins chains to be useful for quantum information processing tasks, the interaction between the spin chain and its environment generally needs to be suppressed. In this paper, we propose the use of strong static and oscillating control…

Quantum Physics · Physics 2019-08-29 Sharoon Austin , Muhammad Qasim Khan , Maryam Mudassar , Adam Zaman Chaudhry

We propose a quantum Wheatstone bridge as a fully quantum analogue to the classical version. The bridge is a few-body boundary-driven spin chain exploiting quantum effects to gain an enhanced sensitivity to an unknown coupling. The…

Quantum Physics · Physics 2022-06-15 Kasper Poulsen , Alan C. Santos , Nikolaj T. Zinner

The Quantum Speed Limit can be found in many different situations, in particular in the propagation of information through quantum spin chains. In homogeneous chains it implies that taking information from one extreme of the chain to the…

Quantum Physics · Physics 2020-12-30 Diego S. Acosta Coden , Sergio S. Gómez , Alejandro Ferrón , Omar Osenda

A large class of optimisation problems can be mapped to the Ising model where all details are encoded in the coupling of spins. The task of the original mathematical optimisation is then equivalent to finding the ground state of the…

We propose dynamical control schemes for Hamiltonian simulation in many-body quantum systems that avoid instantaneous control operations and rely solely on realistic bounded-strength control Hamiltonians. Each simulation protocol consists…

Quantum Physics · Physics 2014-06-25 Adam D. Bookatz , Pawel Wocjan , Lorenza Viola

We consider spin-chain-star systems characterized by N-wise many-body interactions between the spins in each chain and the central one. We show that such systems can be exactly mapped into standard spin-star systems through unitary…

Quantum Physics · Physics 2022-06-22 R. Grimaudo , A. S. M. de Castro , A. Messina , D. Valenti

A quantum system subject to external fields is said to be controllable if these fields can be adjusted to guide the state vector to a desired destination in the state space of the system. Fundamental results on controllability are reviewed…

Nuclear Theory · Physics 2008-11-26 John W. Clark , Dennis G. Lucarelli , Tzyh-Jong Tarn

We analyze a model for spin squeezing based on the so-called counter-twisting Hamiltonian, including the effects of dissipation and finite system size. We discuss the conditions under which the Heisenberg limit, i.e. phase sensitivity…

Quantum Physics · Physics 2009-11-07 A. André , M. D. Lukin

The inverse problem of statistical mechanics involves finding the minimal Hamiltonian that is consistent with some observed set of correlation functions. This problem has received renewed interest in the analysis of biological networks; in…

Neurons and Cognition · Quantitative Biology 2010-12-30 Feraz Azhar , William Bialek