English
Related papers

Related papers: Uncertainty relations in implementation of unitary…

200 papers

A practical way to deal with the problem of time in quantum cosmology and quantum gravity is proposed. The main tool is effective equations, which mainly restrict explicit considerations to semiclassical regimes but have the crucial…

General Relativity and Quantum Cosmology · Physics 2011-07-20 Martin Bojowald , Philipp A Hoehn , Artur Tsobanjan

It is not possible to obtain information about the observable properties of a quantum system without a physical interaction between the system and an external meter. This physical interaction is described by a unitary transformation of the…

Quantum Physics · Physics 2021-07-29 Tomonori Matsushita , Holger F. Hofmann

We theoretically investigate fluctuation relations in a classical incomplete measurement process where just partial information is available. The scenario we consider consists of two coupled single-electron boxes where one or both devices…

Statistical Mechanics · Physics 2015-06-23 Massimo Borrelli , Jonne V. Koski , Sabrina Maniscalco , Jukka P. Pekola

The widely considered assertion is that the unitarity of quantum mechanical evolution assures the preservation of information. It is even promoted in popular literature as an established fact. (Susskind, 2008) Yet, a simple chain of…

Quantum Physics · Physics 2013-11-27 Peter B. Lerner

Time-translation symmetry strongly constrains physical dynamics, yet systematic characterization for continuous-variable systems lags behind its discrete-variable counterpart. We close this gap by providing a rigorous classification of…

The thermodynamic uncertainty relation, originally derived for classical Markov-jump processes, provides a trade-off relation between precision and dissipation, deepening our understanding of the performance of quantum thermal machines.…

Statistical Mechanics · Physics 2021-03-31 Junjie Liu , Dvira Segal

Three recent arguments seek to show that the universal applicability of unitary quantum theory is inconsistent with the assumption that a well-conducted measurement always has a definite physical outcome. In this paper I restate and analyze…

Quantum Physics · Physics 2018-10-17 Richard A. Healey

We derive an upper bound for the time needed to implement a generic unitary transformation in a $d$ dimensional quantum system using $d$ control fields. We show that given the ability to control the diagonal elements of the Hamiltonian,…

Quantum Physics · Physics 2020-04-22 Juneseo Lee , Christian Arenz , Daniel Burgarth , Herschel Rabitz

We establish a relation between the geometric time-energy uncertainty and multipartite entanglement. In particular, we show that the time-energy uncertainty relation is bounded below by the geometric measure of multipartite entanglement for…

Quantum Physics · Physics 2013-03-05 Manabendra Nath Bera , R. Prabhu , Arun Kumar Pati , Aditi Sen De , Ujjwal Sen

Although nonequilibrium work and fluctuation relations have been studied in detail within classical statistical physics, extending these results to open quantum systems has proven to be conceptually difficult. For systems that undergo…

We study the fluctuations of generic currents in multi-terminal, multi-channel quantum transport settings. In the quantum regime, these fluctuations and the resulting precision differ strongly depending on whether the device is of fermionic…

Mesoscale and Nanoscale Physics · Physics 2025-04-08 Didrik Palmqvist , Ludovico Tesser , Janine Splettstoesser

Thermodynamic Uncertainty Relations (TURs) set universal bounds linking current fluctuations to entropy production in nonequilibrium steady states. Their multidimensional generalization (MTUR) introduces matrix inequalities connecting…

Mesoscale and Nanoscale Physics · Physics 2026-05-07 Sergi Vidal , Alba Mayor-Fernandez , Rosa Lopez

The operational formulations of quantum theory are drastically time oriented. However, to the best of our knowledge, microscopic physics is time-symmetric. We address this tension by showing that the asymmetry of the operational…

Quantum Physics · Physics 2021-08-11 Andrea Di Biagio , Pietro Donà , Carlo Rovelli

We analyze the size and evolution of quantum fluctuations of cosmologically relevant geometric observables, in the context of the effective relational cosmological dynamics of GFT models of quantum gravity. We consider the fluctuations of…

General Relativity and Quantum Cosmology · Physics 2021-09-23 Luca Marchetti , Daniele Oriti

In this paper we provide a new set of uncertainty principles for unitary operators using a sequence of inequalities with the help of the geometric-arithmetic mean inequality. As these inequalities are "fine-grained" compared with the…

Quantum Physics · Physics 2019-08-15 Bing Yu , Naihuan Jing , Xianqing Li-Jost

We investigate the question, "how does time flow?" and show that time may change by inversions as well. We discuss its implications to a simple class of linear systems. Instead of introducing any unphysical behaviour, inversions can lead to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Dhurjati Prasad Datta

In this work we study the unitary time-evolutions of quantum systems defined on infinite-dimensional separable time-dependent Hilbert spaces. Two possible cases are considered: a quantum system defined on a stochastic interval and another…

Quantum Physics · Physics 2019-05-22 Luca Curcuraci , Stefano Bacchi , Angelo Bassi

Uncertainty relations in quantum mechanics express bounds on our ability to simultaneously obtain knowledge about expectation values of non-commuting observables of a quantum system. They quantify trade-offs in accuracy between…

Quantum Physics · Physics 2020-03-16 Ilya Kull , Philippe Allard Guérin , Frank Verstraete

We introduce a novel algorithm for the task of coherently controlling a quantum mechanical system to implement any chosen unitary dynamics. It performs faster than existing state of the art methods by one to three orders of magnitude…

Quantum Physics · Physics 2015-06-04 Pierre de Fouquieres

The thermodynamic uncertainty relation expresses a universal trade-off between precision and entropy production, which applies in its original formulation to current observables in steady-state systems. We generalize this relation to…

Statistical Mechanics · Physics 2018-12-06 Timur Koyuk , Udo Seifert , Patrick Pietzonka
‹ Prev 1 4 5 6 7 8 10 Next ›