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We provide a justification of the quantum speed-up based on the complementary roles played by the reversible preparation of an entangled state before measurement and by the final measurement action.

Quantum Physics · Physics 2007-05-23 Giuseppe Castagnoli , Dalida Monti , Alexander Sergienko

Quantum speed limits (QSLs) identify fundamental time scales of physical processes by providing lower bounds on the rate of change of a quantum state or the expectation value of an observable. We introduce a generalization of QSL for…

Quantum Physics · Physics 2022-12-28 Nicoletta Carabba , Niklas Hörnedal , Adolfo del Campo

Uncertainties in the frequency parameters of a frequency comb laser, causes it to represent a mixed quantum state. The formulation of such a quantum state is compounded by the fact that it contains both particle-number degrees of freedom…

Quantum Physics · Physics 2017-06-05 Filippus S. Roux

We probe the quantum speed limit (QSL) of an electron when it is trapped in a non-uniform magnetic field. We show that the QSL increases to a large value, but within the regime of causality, by choosing a proper variation in magnetic…

Quantum Physics · Physics 2022-08-26 Srishty Aggarwal , Subhashish Banerjee , Arindam Ghosh , Banibrata Mukhopadhyay

We give a lower bound on the probability of error in quantum state discrimination. The bound is a weighted sum of the pairwise fidelities of the states to be distinguished.

Quantum Physics · Physics 2016-11-15 Ashley Montanaro

One of the fundamental physical limits on the speed of time evolution of a quantum state is known in the form of the celebrated Mandelstam-Tamm inequality. This inequality gives an answer to the question on how fast an isolated quantum…

Quantum Physics · Physics 2022-04-14 Sergio Albeverio , Alexander K. Motovilov

Any physical system evolves at a finite speed that is constrained not only by the energetic cost but also by the topological structure of the underlying dynamics. In this Letter, by considering such structural information, we derive a…

Quantum Physics · Physics 2023-01-06 Tan Van Vu , Keiji Saito

The speed of elementary quantum gates ultimately sets the limit on the speed at which quantum circuits can operate. For a fixed physical interaction strength between two qubits, the speed of any two-qubit gate is limited even with…

Quantum Physics · Physics 2023-12-15 Bora Basyildiz , Casey Jameson , Zhexuan Gong

We discuss single adaptive measurements for the estimation of mixed quantum states of qubits. The results are compared to the optimal estimation schemes using collective measurements. We also demonstrate that the advantage of collective…

Quantum Physics · Physics 2009-11-06 Dietmar G. Fischer , Matthias Freyberger

How fast an observable can evolve in time is answered by so-called ``observable speed limit". Here, we prove a stronger version of the observable speed limit and show that the previously obtained bound is a special case of the new bound.…

Quantum Physics · Physics 2024-12-09 Divyansh Shrimali , Biswaranjan Panda , Arun Kumar Pati

Quantum speed limit focuses on the minimum time scale for a fixed mission and hence is important in quantum information where fast dynamics is usually beneficial. Most existing tools for the depiction of quantum speed limit are the…

Quantum Physics · Physics 2023-10-09 Mao Zhang , Huai-Ming Yu , Jing Liu

We investigate the relationship between quantum speed limit time and the non-Markovianity of an atom in structured environments. We show that there exists an inverse relation between them, which means that the non-Markovian feature of the…

Quantum Physics · Physics 2023-12-27 Maryam Hadipour , Soroush Haseli , Saeed Haddadi

Bounds to the speed of evolution of a quantum system are of fundamental interest in quantum metrology, quantum chemical dynamics and quantum computation. We derive a time-energy uncertainty relation for open quantum systems undergoing a…

Quantum Physics · Physics 2013-03-05 A. del Campo , I. L. Egusquiza , M. B. Plenio , S. F. Huelga

The question of how fast a quantum state can evolve has attracted a considerable attention in connection with quantum measurement, metrology, and information processing. Since only orthogonal states can be unambiguously distinguished, a…

Quantum Physics · Physics 2015-05-13 Lev B. Levitin , Tommaso Toffoli

Given a mixture of states, finding a way to optimally discriminate its elements is a prominent problem in quantum communication theory. In this paper, we will address mixtures of density operators that are unitarily equivalent via elements…

Mathematical Physics · Physics 2024-02-09 Alberto Acevedo , Janek Wehr

The quantum speed limit time for quantum system under squeezed environment is studied. We consider two typical models, the damped Jaynes-Cummings model and the dephasing model. For the damped Jaynes-Cummings model under squeezed…

Quantum Physics · Physics 2021-10-08 Kang-ying Du , Ya-jie Ma , Shao-xiong Wu , Chang-shui Yu

Quantum mechanics imposes a fundamental bound on the minimum time required for the quantum systems to evolve between two states of interest. This bound introduces a limit on the speed of the dynamical evolution of the systems, known as the…

High Energy Physics - Theory · Physics 2020-08-19 Yusef Maleki , Alireza Maleki

Quantum fidelity is a central tool in quantum information, quantifying how much two quantum states are similar. Here we propose a limit formula for the quantum fidelity between a mixed state and a pure state. As an example of an…

Quantum Physics · Physics 2014-10-13 Gaetana Spedalieri , Christian Weedbrook , Stefano Pirandola

The speed of quantum evolution is limited under finite energy resources. While most quantum speed limits (QSLs) are formulated in terms of quantum states, they can be extended to the evolution operator itself, and thus impose fundamental…

Quantum Physics · Physics 2026-04-28 Hunter Nelson , Edwin Barnes

In this paper, we give a mechanism for controlling speedup of a single-qubit open quantum system by exclusively manipulating the system-reservoir bound states using additional non-interacting qubits. It is demonstrated that providing…

Quantum Physics · Physics 2017-05-31 N. Behzadi , B. Ahansaz , A. Ektesabi , E. Faizi
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