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Related papers: Two-State Quantum Systems Revisited: a Geometric A…

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The random matrix ensembles are applied to the quantum statistical two-dimensional systems of electrons. The quantum systems are studied using the finite dimensional real, complex and quaternion Hilbert spaces of the eigenfunctions. The…

Statistical Mechanics · Physics 2015-06-24 Maciej M. Duras

We extend the application of the techniques developed within the framework of the pseudo-Hermitian quantum mechanics to study a unitary quantum system described by an imaginary PT-symmetric potential v(x) having a continuous real spectrum.…

Quantum Physics · Physics 2009-11-11 Ali Mostafazadeh

Geometric Algebra and Calculus are mathematical languages encoding fundamental geometric relations that theories of physics seem to respect. We propose criteria given which statistics of expressions in geometric algebra are computable in…

Quantum Physics · Physics 2020-12-16 Ross N. Greenwood

The Generator Coordinate Method (GCM) in the Gaussian Overlap Approximation (GOA) is applied to a description of the nuclear quadrupole collective states. The full five-dimensional quadrupole tensor is used as a set of the generator…

Nuclear Theory · Physics 2015-06-04 Stanisław G. Rohoziński

The formalism of geometric algebra can be described as deformed super analysis. The deformation is done with a fermionic star product, that arises from deformation quantization of pseudoclassical mechanics. If one then extends the…

Mathematical Physics · Physics 2009-11-10 Peter Henselder , Allen C. Hirshfeld , Thomas Spernat

A mixed quantum state is represented by a Hermitian positive semi-definite operator $\rho$ with unit trace. The positivity requirement is responsible for a highly nontrivial geometry of the set of quantum states. A known way to satisfy this…

Quantum Physics · Physics 2020-02-18 N. Il'in , E. Shpagina , F. Uskov , O. Lychkovskiy

A geometric approach to general quantum statistical systems (including the harmonic oscillator) is presented. It is applied to Casimir energy and the dissipative system with friction. We regard the (N+1)-dimensional Euclidean {\it…

High Energy Physics - Theory · Physics 2011-01-28 Shoichi Ichinose

Polynomially-large ground-state energy gaps are rare in many-body quantum systems, but useful for adiabatic quantum computing. We show analytically that the gap is generically polynomially-large for quadratic fermionic Hamiltonians. We then…

Quantum Physics · Physics 2013-05-29 Michael J. O'Hara , Dianne P. O'Leary

Based on empirical evidence, quantum systems appear to be strictly linear and gauge invariant. This work uses concise mathematics to show that quantum eigenvalue equations on a one dimensional ring can either be gauge invariant or have a…

Quantum Physics · Physics 2014-07-15 Arthur Davidson

We have previously presented a version of the Weak Equivalence Principle for a quantum particle as an exact analog of the classical case, based on the Heisenberg picture analysis of free particle motion. Here, we take that to a full…

General Relativity and Quantum Cosmology · Physics 2025-06-17 Otto C. W. Kong

Using the quantum Hamiltonian for a gravitational system with boundary, we find the partition function and derive the resulting thermodynamics. The Hamiltonian is the boundary term required by functional differentiability of the action for…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Seth A. Major , Kevin L. Setter

Quantum systems are viewed as emergent systems from the fundamental degrees of freedom. The laws and rules of quantum mechanics are understood as an effective description, valid for the emergent systems and specially useful to handle…

Mathematical Physics · Physics 2025-11-26 Ricardo Gallego Torromé

We in this paper study the quantization of a particle in an inverted potential well. The Hamiltonian is Hermitian, while the potential is unbounded below. Classically the particle moves away acceleratingly from the center of potential top.…

Quantum Physics · Physics 2025-05-06 Ni Liu , J. -Q. Liang

We provide a graphical method to describe and analyze non-Gaussian quantum states using a hypergraph framework. These states are pivotal resources for quantum computing, communication, and metrology, but their characterization is hindered…

Quantum Physics · Physics 2025-07-28 Lina Vandré , Boxuan Jing , Yu Xiang , Otfried Gühne , Qiongyi He

We establish a connection between ground states of local quantum Hamiltonians and thermal states of classical spin systems. For any discrete classical statistical mechanical model in any spatial dimension, we find an associated quantum…

Quantum Physics · Physics 2012-03-05 W. Dür , M. Van den Nest

This work is concerned with the notion of {eigenstates} for $C^*$-algebras. After reviewing some basic and structural results, we explore the possibility of reinterpreting certain typical concepts of quantum mechanics (\eg dynamical…

Mathematical Physics · Physics 2023-04-07 Giuseppe De Nittis , Danilo Polo

Ground-state preparation for a given Hamiltonian is a common quantum-computing task of great importance and has relevant applications in quantum chemistry, computational material modeling, and combinatorial optimization. We consider an…

Quantum Physics · Physics 2022-10-18 Yu-Qin Chen , Shi-Xin Zhang , Chang-Yu Hsieh , Shengyu Zhang

A set of Hamiltonians that are not self-adjoint but have the spectrum of the harmonic oscillator is studied. The eigenvectors of these operators and those of their Hermitian conjugates form a bi-orthogonal system that provides a…

Quantum Physics · Physics 2017-11-23 Oscar Rosas-Ortiz , Kevin Zelaya

We introduce a new technique for dealing with the matrix elements of the Hamiltonian operator in loop quantum gravity, based on the use of intertwiners projected on coherent states of angular momentum. We give explicit expressions for the…

General Relativity and Quantum Cosmology · Physics 2016-10-26 Emanuele Alesci , Jerzy Lewandowski , Ilkka Mäkinen

In quantum mechanics, predictions are made by way of calculating expectation values of observables, which take the form of Hermitian operators. It is far less common to exploit non-Hermitian operators to perform measurements. Here, we show…

Quantum Physics · Physics 2015-11-04 Eliot Bolduc , Genevieve Gariepy , Jonathan Leach