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The controllability property of the unitary propagator of an N-level quantum mechanical system subject to a single control field is described using the structure theory of semisimple Lie algebras. Sufficient conditions are provided for the…

Quantum Physics · Physics 2009-11-07 Claudio Altafini

A fundamental problem in quantum engineering is determining the lowest time required to ensure that all possible unitaries can be generated with the tools available, which is one of a number of possible quantum speed limits. We examine this…

Quantum Physics · Physics 2023-11-03 Mattias T. Johnsson , Lauritz van Luijk , Daniel Burgarth

We consider the problem of setting up the Wigner distribution for states of a quantum system whose configuration space is a Lie group. The basic properties of Wigner distributions in the familiar Cartesian case are systematically…

Quantum Physics · Physics 2015-06-26 N. Mukunda , Arvind , S. Chaturvedi , R. Simon

In this paper, we define four different notions of controllability of physical interest for multilevel quantum mechanical systems. These notions involve the possibility of driving the evolution operator as well as the state of the system.…

Quantum Physics · Physics 2007-05-23 F. Albertini , D. D'Alessandro

We consider the problem of controlling in minimum time a two-level quantum system which can be subject to a drift. The control is assumed to be bounded in magnitude, and to affect two or three independent generators of the dynamics. We…

Quantum Physics · Physics 2015-10-28 Raffaele Romano

Quantum phenomena of interest in connection with applications to computation and communication almost always involve generating specific transfers between eigenstates, and their linear superpositions. For some quantum systems, such as spin…

Quantum Physics · Physics 2016-11-18 A. M. Bloch , R. W. Brockett , C. Rangan

For a quantum-mechanically spread-out particle we investigate a method for determining its arrival time at a specific location. The procedure is based on the emission of a first photon from a two-level system moving into a laser-illuminated…

Quantum Physics · Physics 2009-11-07 J. A. Damborenea , I. L. Egusquiza , G. C. Hegerfeldt , J. G. Muga

The notion of quantum speed limit (QSL) refers to the fundamental fact that two quantum states become completely distinguishable upon dynamical evolution only after a finite amount time, called the QSL time. A different, but related concept…

Quantum Physics · Physics 2019-04-29 Pablo M. Poggi

This paper provides a framework for the control of quantum mechanical systems with scattering states, i.e., systems with continuous spectra. We present the concept and prove a criterion of the approximate strong smooth controllability. Our…

Quantum Physics · Physics 2007-05-23 Re-Bing Wu , Tzyh-Jong Tarn , Chun-Wen Li

In this paper we investigate the limits of control for mixed-state quantum systems. The constraint of unitary evolution for non-dissipative quantum systems imposes kinematical bounds on the optimization of arbitrary observables. We…

Quantum Physics · Physics 2009-02-05 S. G. Schirmer , J. V. Leahy

We propose a gate-based quantum algorithm for the prediction step of Bayesian state estimation based on the Fokker-Planck equation on a discretized position-velocity state space. The probability density is encoded in the amplitudes of a…

Quantum Physics · Physics 2026-04-28 Felix Govaers

Ensemble systems appear frequently in many engineering applications and, as a result, they have become an important research topic in control theory. These systems are best characterized by the evolution of their underlying state…

Optimization and Control · Mathematics 2026-01-21 Guangyu Wu , Panagiotis Tsiotras , Anders Lindquist

Geometric effects make evolution time vary for different evolution curves that connect the same two quantum states. Thus, it is important to be able to control along which path a quantum state evolve to achieve maximal speed in quantum…

Quantum Physics · Physics 2013-05-01 Ole Andersson , Hoshang Heydari

In this paper we develope the main ideas of the quantized version of affinely-rigid (homogeneously deformable) motion. We base our consideration on the usual Schr\"odinger formulation of quantum mechanics in the configuration manifold which…

This paper aims to explore the inherent connection among Heisenberg groups, quantum Fourier transform and (quasiprobability) distribution functions. Distribution functions for continuous and finite quantum systems are examined first as a…

Mathematical Physics · Physics 2015-05-18 Manas K. Patra , Samuel L. Braunstein

This paper examines the controllability for quantum control systems with SU(1,1) dynamical symmetry, namely, the ability to use some electromagnetic field to redirect the quantum system toward a desired evolution. The problem is formalized…

Optimization and Control · Mathematics 2007-08-24 Jian-Wu Wu , Chun-Wen Li , Jing Zhang , Tzyh-Jong Tarn

Reconfigurable distribution of entangled states is essential for operation of quantum networks connecting multiple devices such as quantum memories and quantum computers. We introduce new quantum distribution network architecture enabling…

Quantum Physics · Physics 2021-08-05 Shuto Osawa , David S. Simon , Vladimir S. Malinovsky , Alexander V. Sergienko

We investigate modifications of quantum mechanics (QM) that replace the unitary group in a finite dimensional Hilbert space with a finite group and determine the minimal sequence of subgroups necessary to approximate QM arbitrarily closely…

High Energy Physics - Theory · Physics 2020-01-30 T. Banks

The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off…

Quantum Physics · Physics 2015-12-08 Miroslav Gajdacz , Kunal K. Das , Jan Arlt , Jacob F. Sherson , Tomáš Opatrný

We demonstrate how structured decompositions of unitary operators can be employed to derive control schemes for finite-level quantum systems that require only sequences of simple control pulses such as square wave pulses with finite rise…

Quantum Physics · Physics 2009-11-07 S. G. Schirmer , A. D. Greentree , V. Ramakrishna , H. Rabitz
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