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In quantum systems, a plausible definition of work is based on two energy measurement scheme. Considering that energy change of quantum system obeys a time-energy uncertainty relation, it shall be interesting to see whether such type of…

Statistical Mechanics · Physics 2016-08-03 Fei Liu

We study the quantum-mechanical uncertainty relation originating from the successive measurement of two observables $\hat{A}$ and $\hat{B}$, with eigenvalues $a_n$ and $b_m$, respectively, performed on the same system. We use an extension…

Quantum Physics · Physics 2020-06-02 Ady Mann , Pier A. Mello , Michael Revzen

A quantum system can be described and characterized by at least two different concepts, namely, its physical and informational properties. Here, we explicitly connect these two concepts, by equating the time-energy cost which is the product…

Quantum Physics · Physics 2014-09-03 Chi-Hang Fred Fung , H. F. Chau

We consider Hamiltonian quantum systems with energy bandwidth \Delta E and show that each measurement that determines the time up to an error \Delta t generates at least the entropy (\hbar/(\Delta t \Delta E))^2/2. Our result describes…

Quantum Physics · Physics 2007-05-23 Dominik Janzing , Thomas Beth

The experimental determination of entanglement is a major goal in the quantum information field. In general the knowledge of the state is required in order to quantify its entanglement. Here we express a lower bound to the robustness of…

Quantum Physics · Physics 2007-05-23 Daniel Cavalcanti , Marcelo O. Terra Cunha

The investigation of thermalization in isolated quantum many-body systems has a long history, dating back to the time of developing statistical mechanics. Most quantum many-body systems in nature are considered to thermalize, while some…

Statistical Mechanics · Physics 2021-08-25 Naoto Shiraishi , Keiji Matsumoto

We establish a physically meaningful representation of a quantum energy density for use in Quantum Monte Carlo calculations. The energy density operator, defined in terms of Hamiltonian components and density operators, returns the correct…

Materials Science · Physics 2013-08-09 Jaron T. Krogel , Min Yu , Jeongnim Kim , David M. Ceperley

We present a method to estimate the probabilities of outcomes of a quantum observable, its mean value, and higher moments by measuring any other observable. This method is general and can be applied to any quantum system. In the case of…

Quantum Physics · Physics 2023-08-16 Dominik Šafránek , Dario Rosa

When manipulating a quantum system $S$, its surrounding system, or \textit{environment}, $E$ induces unwanted effects. It is mainly due to its vastness and the lack of knowledge about the Hamiltonian $H_{SE}$ that governs the dynamics…

Quantum Physics · Physics 2015-03-05 Masaki Owari , Koji Maruyama , Takeji Takui , Go Kato

Thermalization is the process through which a physical system evolves toward a state of thermal equilibrium. Determining whether or not a physical system will thermalize from an initial state has been a key question in condensed matter…

Quantum Physics · Physics 2026-01-05 Dhruv Devulapalli , T. C. Mooney , James D. Watson

We discuss what kind of quantum channels can enable thermalization processes. We show that in order to determine a system's temperature, a thermometer needs to dynamically gain information about the system's local Hamiltonian and not just…

Quantum Physics · Physics 2021-11-09 Daniel Grimmer , Robert B. Mann , Eduardo Martin-Martinez

Determining the energy levels of a quantum system is a significant task, for instance, to analyze reaction rates in drug discovery and catalysis or characterize the compatibility of materials. In this paper we exploit quantum metrology, the…

Following the evolution of an open quantum system requires full knowledge of its dynamics. In this paper we consider open quantum systems for which the Hamiltonian is ``uncertain''. In particular, we treat in detail a simple system similar…

Quantum Physics · Physics 2009-11-07 Jay Gambetta , H. M. Wiseman

Exact conditions on the clock parameters corresponding to the minimal uncertainty in distance measurement are derived in uniform manner for any number of space time dimensions. The result espouses the holography principle no matter what the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michael Maziashvili

A quantum state for being an eigenstate of some local Hamiltonian should be constraint by zero energy variance and consequently, the constraint is rather strong that a single eigenstate may uniquely determine the Hamiltonian. For…

Quantum Physics · Physics 2024-12-17 Xu-Dan Xie , Zheng-Yuan Xue , Dan-Bo Zhang

Hamiltonian Truncation (HT) is a numerical approach for calculating observables in a Quantum Field Theory non-perturbatively. This approach can be applied to theories constructed by deforming a conformal field theory with a relevant…

High Energy Physics - Theory · Physics 2022-04-27 Joan Elias Miro , James Ingoldby

We consider the problem of learning the Hamiltonian of a quantum system from estimates of Gibbs-state expectation values. Various methods for achieving this task were proposed recently, both from a practical and theoretical point of view.…

Quantum Physics · Physics 2024-10-31 Adam Artymowicz , Hamza Fawzi , Omar Fawzi , Samuel O. Scalet

Most classical mechanical systems are based on dynamical variables whose values are real numbers. Energy conservation is then guaranteed if the dynamical equations are phrased in terms of a Hamiltonian function, which then leads to…

Mathematical Physics · Physics 2013-12-05 Gerard 't Hooft

We introduce a general framework for defining context-dependent time distributions in quantum systems using projective measurements. The time-of-flow (TF) distribution, derived from population transfer rates into a measurement subspace,…

Quantum Physics · Physics 2025-11-17 Mathieu Beau

We consider quantum systems with a Hamiltonian containing a weak perturbation i.e. $\boldsymbol{H=H_0} + \boldsymbol{\lambda} \cdot \boldsymbol{\tilde{H}}$, $\boldsymbol{\lambda}= \{\lambda_1, \lambda_2,...\}$, $\boldsymbol{\tilde{H}}$ $=…

Quantum Physics · Physics 2025-02-18 Sidali Mohammdi , Matteo Bina , Abdelhakim Gharbi , Matteo G. A. Paris
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