English
Related papers

Related papers: Absence of Quantum States Corresponding to Unstabl…

200 papers

A unified conceptual foundation of classical and quantum physics is given, free of undefined terms. Ensembles are defined by extending the `probability via expectation' approach of Whittle to noncommuting quantities. This approach carries…

Quantum Physics · Physics 2007-05-23 Arnold Neumaier

A quantum state of the entire cosmos (universe or multiverse) is proposed which is the equal mixture of the Giddings-Marolf states that are asymptotically single de Sitter spacetimes in both past and future and are regular on the throat or…

High Energy Physics - Theory · Physics 2008-11-26 Don N. Page

We obtained the analog of the Luttinger relation for a commensurate spin-density-wave state. We show that while the relation between the area of the occupied states and the density of particles gets modified in a simple and predictable way…

Strongly Correlated Electrons · Physics 2009-10-30 B. L. Altshuler , A. V. Chubukov , A. Dashevskii , A. M. Finkel'stein , D. K. Morr

The quantum no-broadcasting theorem has an analogue in modal quantum theory (MQT), a toy model based on finite fields. The failure of broadcasting in MQT is related to the failure of distributivity of the lattice of subspaces of the state…

Quantum Physics · Physics 2023-04-27 Phillip Diamond , Benjamin Schumacher , Michael D. Westmoreland

The classical limit $\hbar$->0 of quantum mechanics is known to be delicate, in particular there seems to be no simple derivation of the classical Hamilton equation, starting from the Schr\"odinger equation. In this paper I elaborate on an…

Mathematical Physics · Physics 2011-07-29 Christoph Nölle

We argue that the conventional quantum field theory in curved spacetime has a grave drawback: The canonical commutation relations for quantum fields and conjugate momenta do not hold. Thus the conventional theory should be denounced and the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Vladimir S. Mashkevich

We show (i) the existence of universal resource states for a certain class of linear Hamiltonians and (ii) the uselessness of highly entangled states for quantum metrology of linear Hamiltonians. We also show that random pure states are…

Quantum Physics · Physics 2025-10-10 Rina Miyajima , Yuki Takeuchi , Seiseki Akibue

It is nowadays accepted that truly quantum correlations can exist even in the absence of entanglement. For the case of symmetric states, a physically trivial unitary transformation can alter a quantum state from entangled to separable and…

Quantum Physics · Physics 2022-02-24 Aaron Z. Goldberg , Markus Grassl , Gerd Leuchs , Luis L. Sánchez-Soto

In this work, we reveal a new type of impossibility discovered in our recent research which forbids comparing the closeness of multiple unknown quantum states with any non-trivial threshold in a perfect or an unambiguous way. This…

Quantum Physics · Physics 2015-05-30 Shengshi Pang , Shengjun Wu , Zeng-Bing Chen

Quantum field theory on curved spacetimes lacks an obvious distinguished vacuum state. We review a recent no-go theorem that establishes the impossibility of finding a preferred state in each globally hyperbolic spacetime, subject to…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Christopher J. Fewster

Quantum-mechanical analysis shows that the metrics of a centrally symmetric uncharged gravitational field, which are exact solutions of the general relativity equations, are physically non-equivalent. The classical Schwarzschield metric and…

General Relativity and Quantum Cosmology · Physics 2013-08-05 M. V. Gorbatenko , V. P. Neznamov

The general problem of performance advantage obtainable by the use of nonclassical transmitted states over classical ones is considered. Attention is focused on the situation where system loss is significant and additive Gaussian noise may…

Quantum Physics · Physics 2012-12-05 Horace P. Yuen , Ranjith Nair

We study the third quantization of the Friedmann-Robertson-Walker cosmology with $N$-minimal massless fields. The third quantized Hamiltonian for the WDW equation in the minisuperspace consists of infinite number of intrinsic…

General Relativity and Quantum Cosmology · Physics 2012-12-24 Sang Pyo Kim

The aim of the paper is to study the question whether or not equilibrium states exist in open quantum systems that are embedded in at least two environments and are described by a non-Hermitian Hamilton operator $\cal H$. The eigenfunctions…

Quantum Physics · Physics 2018-11-27 Ingrid Rotter

A concept -- quantum order -- is introduced to describe a new kind of orders that generally appear in quantum states at zero temperature. Quantum orders that characterize universality classes of quantum states (described by {\em complex}…

Strongly Correlated Electrons · Physics 2009-11-07 Xiao-Gang Wen

Quantum systems often exhibit fundamental incapability to entertain vortex. The Meissner effect, a complete expulsion of the magnetic field (the electromagnetic vorticity), for instance, is taken to be the defining attribute of the…

Quantum Physics · Physics 2016-01-01 Z. Yoshida , S. M. Mahajan

We develop a novel approach to Quantum Mechanics that we call Curved Quantum Mechanics. We introduce an infinite-dimensional K\"ahler manifold ${\cal M}$, that we call the state manifold, such that the cotangent space $T_z^*{\cal M}$ is a…

Quantum Physics · Physics 2024-12-12 Ivan G. Avramidi , Roberto Niardi

We present a new hydrodynamic analogy of nonrelativistic quantum particles in potential wells. Similarities between a real variant of the Schr\"odinger equation and gravity-capillary shallow water waves are reported and analyzed. We show…

Quantum Physics · Physics 2024-10-01 Idan Ceausu , Yuval Dagan

We study both the classical and quantum rotational dynamics of an asymmetric top molecule, controlled through three orthogonal electric fields that interact with its dipole moment. The main difficulties in studying the controllability of…

Mathematical Physics · Physics 2021-10-01 Eugenio Pozzoli

It is demonstrated that, making minimal changes in ordinary quantum mechanics, a reasonable irreversible quantum mechanics can be obtained. This theory has a more general spectral decompositions, with eigenvectors corresponding to unstable…

Quantum Physics · Physics 2007-05-23 Mario Castagnino , Roberto Laura