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We investigate the relation between the entanglement properties of a quantum state and its energy for macroscopic spin models. To this aim, we develop a general method to compute energy bounds for states without certain forms of…

Quantum Physics · Physics 2007-05-23 Otfried Gühne , Geza Toth

We study the Casimir problem as the limit of a conventional quantum field theory coupled to a smooth background. The Casimir energy diverges in the limit that the background forces the field to vanish on a surface. We show that this…

High Energy Physics - Theory · Physics 2008-11-26 N. Graham , R. L. Jaffe , V. Khemani , M. Quandt , M. Scandurra , H. Weigel

The exact solution of the Dirac equation and the spectrum of electron quasi-energies in a superposition of the field of a circularly polarized electromagnetic wave and a homogeneous magnetic field parallel to the direction of wave…

Accelerator Physics · Physics 2007-05-23 R. A. Melikian , D. P. Barber

Phantom energy which violates the dominant-energy condition and is not excluded by current constraints on the equation of state may be dominating the evolution of the universe now. It has been pointed out that in such a case the fate of the…

Astrophysics · Physics 2009-11-07 Pedro F. Gonzalez-Diaz

The energy of magnetic moment of the persistent current circulating in superconducting loop in an externally produced magnetic field is not taken into account in the theory of quantization effects because of identification of the…

Superconductivity · Physics 2015-01-05 V. L. Gurtovoi , A. V. Nikulov

We reanalyze the problem of a 1D Dirac single particle colliding with the electrostatic potential step of height $V_{0}$ with a positive incoming energy that tends to the limit point of the so-called Klein energy zone, i.e., $E\rightarrow…

Quantum Physics · Physics 2023-03-01 Salvatore De Vincenzo

We explore the connections between the constraints on the precision of quantum logical operations that arise from a conservation law, and those arising from quantum field fluctuations. We show that the conservation-law based constraints…

Quantum Physics · Physics 2009-11-11 Julio Gea-Banacloche , Masanao Ozawa

A lower bound on the amount of energy needed to carry out an elementary logical operation on a qubit system, with a given accuracy and in a given time, has been recently postulated. This paper is an attempt to formalize this bound and…

Quantum Physics · Physics 2007-05-23 Julio Gea-Banacloche

We investigate far from equilibrium energy transport in strongly coupled quantum critical systems. Combining results from gauge-gravity duality, relativistic hydrodynamics, and quantum field theory, we argue that long-time energy transport…

High Energy Physics - Theory · Physics 2015-06-03 M. J. Bhaseen , Benjamin Doyon , Andrew Lucas , Koenraad Schalm

In Dirac's hole theory the vacuum state is assumed to be the state where all negative energy states are occupied and all positive energy states are unoccupied. This is often referred to as the Dirac sea. It is generally assumed that the…

General Physics · Physics 2012-08-08 Dan Solomon

Given a closed quantum system, the states that can be reached with a cyclic process are those with the same spectrum as the initial state. Here we prove that, under a very general assumption on the Hamiltonian, the distribution of the mean…

Quantum Physics · Physics 2021-08-04 Raffaele Salvia , Vittorio Giovannetti

It is argued from geometrical, group-theoretical and physical points of view that in the framework of QCD it is not only necessary but also possible to modify the Dirac equation so that correspondence principle holds valid. The Dirac wave…

High Energy Physics - Theory · Physics 2007-05-23 Ivanhoe Pestov

We consider the physical situations where the resource theories of coherence and thermodynamics play competing roles. In particular, we study the creation of quantum coherence using unitary operations with limited thermodynamic resources.…

Quantum Physics · Physics 2016-06-01 Avijit Misra , Uttam Singh , Samyadeb Bhattacharya , Arun Kumar Pati

We introduce the Feynman-Kac formula within the deformation quantization program. Constructing on previous work it is shown that, upon a Wick rotation, the ground state energy of any prescribed physical system can be obtained from the…

Mathematical Physics · Physics 2025-02-07 Jasel Berra-Montiel , Hugo Garcia-Compean , Alberto Molgado

The imposition of boundary conditions upon a quantized field can lead to singular energy densities on the boundary. We treat the boundaries as quantum mechanical objects with a nonzero position uncertainty, and show that the singular energy…

Quantum Physics · Physics 2009-10-31 L. H. Ford , N. F. Svaiter

There has been an enduring interest and controversy about whether or not one can define physically meaningful energy density and stress fields, $e(\bf{r})$ and $\sigma_{\alpha \beta}(\bf{r})$, since the two forms of the kinetic energy,…

Materials Science · Physics 2025-11-17 Richard M. Martin , Nithaya Chetty , Dallas R. Trinkle

The second law of thermodynamics places a limitation into which states a system can evolve into. For systems in contact with a heat bath, it can be combined with the law of energy conservation, and it says that a system can only evolve into…

Quantum Physics · Physics 2015-11-20 Piotr Ćwikliński , Michał Studziński , Michał Horodecki , Jonathan Oppenheim

The difference between quantum isoenergetic process and quantum isothermal process comes from the violation of the law of equipartition of energy in the quantum regime. To reveal an important physical meaning of this fact, here we study a…

General Physics · Physics 2016-06-10 Shengnan Liu , Congjie Ou

Quantum dynamics of a Dirac particle in a 1D box with moving wall is studied. Dirac equation with time-dependent boundary condition is mapped onto that with static one, but with time-dependent mass. Exact analytical solution of such…

Quantum Physics · Physics 2024-06-20 J. Dittrich , S. Rakhmanov , D. Matrasulov

Extracting work from quantum system is one of the important areas in quantum thermodynamics. As a significant thermodynamic quantity, the ergotropy gap characterizes the difference between the global and local maximum extractable works. We…

Quantum Physics · Physics 2022-07-26 Ya-Juan Wu , Shao-Ming Fei , Zhi-Xi Wang , Ke Wu