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We consider a free quantum particle in one dimension whose mass profile exhibits jump discontinuities. The corresponding Hamiltonian is a self-adjoint realisation of the kinetic-energy operator, with the specific realisation determined by…

Mathematical Physics · Physics 2026-04-27 Fabio Deelan Cunden , Giovanni Gramegna , Marilena Ligabò

Simulation of quantum systems is notoriously challenging for classical computers, while quantum hardware is naturally well-suited for this task. However, the imperfections of contemporary quantum systems poses a considerable challenge in…

Quantum Physics · Physics 2025-01-10 Yotam Shapira , Jovan Markov , Nitzan Akerman , Ady Stern , Roee Ozeri

The quantization of a single particle without spin in an appropriate curved space-time is considered. The Hamilton formalism on reduced space for a particle in a curved space-time is constructed and the main aspects of quantization scheme…

General Relativity and Quantum Cosmology · Physics 2007-05-23 D. A. Kalinin

Described is n-level quantum system realized in the n-dimensional ''Hilbert'' space H with the scalar product G taken as a dynamical variable. The most general Lagrangian for the wave function and G is considered. Equations of motion and…

Mathematical Physics · Physics 2008-05-28 Vasyl Kovalchuk , Jan Jerzy Slawianowski

An effective time-dependent Hamiltonian can be implemented by making a quantum system fly through an inhomogeneous potential, realizing, for example, a quantum gate on its internal degrees of freedom. However, flying systems have a spatial…

Quantum Physics · Physics 2024-06-13 Nicolò Piccione , Léa Bresque , Andrew N. Jordan , Robert S. Whitney , Alexia Auffèves

Learning the structure of the entanglement Hamiltonian (EH) is central to characterizing quantum many-body states in analog quantum simulation. We describe a protocol where spatial deformations of the many-body Hamiltonian, physically…

Quantum computing is increasingly offering concrete solutions toward the simulation of nuclear structure, with the potential to overcome the exponential scaling that limits classical diagonalization methods in large spaces. A particularly…

Nuclear Theory · Physics 2026-04-14 Emanuele Costa , Javier Menendez

We propose a quantum algorithm to obtain the lowest eigenstate of any Hamiltonian simulated by a quantum computer. The proposed algorithm begins with an arbitrary initial state of the simulated system. A finite series of transforms is…

Quantum Physics · Physics 2015-01-08 Jeongho Bang , Seung-Woo Lee , Chang-Woo Lee , Hyunseok Jeong

We derive an exact expression for the quantumness of a Hilbert space (defined in quant-ph/0302092), and show that in composite Hilbert spaces the signal states must contain at least some entangled states in order to achieve such a…

Quantum Physics · Physics 2007-05-23 Christopher A. Fuchs

In approaches to quantum gravity, where smooth spacetime is an emergent approximation of a discrete Planckian fundamental structure, any standard effective field theoretical description will miss part of the degrees of freedom and thus…

General Relativity and Quantum Cosmology · Physics 2019-11-04 Lautaro Amadei , Alejandro Perez

Quantum computers have the potential to explore the vast Hilbert space of entangled states that play an important role in the behavior of strongly interacting matter. This opportunity motivates reconsidering the Hamiltonian formulation of…

High Energy Physics - Lattice · Physics 2021-01-08 David B. Kaplan , Jesse R. Stryker

Real quantum systems couple to their environment and lose their intrinsic quantum nature through the process known as decoherence. Here we present a method for minimizing decoherence by making it energetically unfavorable. We present a…

Quantum Physics · Physics 2009-11-06 D. Bacon , K. R. Brown , K. B. Whaley

A quantum theory is constructed for the system of a relativistic particle with mass m moving freely on the SL(2,R) group manifold. Applied to the cotangent bundle of SL(2,R), the method of Hamiltonian reduction allows us to split the…

High Energy Physics - Theory · Physics 2009-10-28 G. Jorjadze L. O'Raifeartaigh I. Tsutsui

We show that Nechiporuk's method for proving lower bounds for Boolean formulas can be extended to the quantum case. This leads to an $\Omega(n^2 / \log^2 n)$ lower bound for quantum formulas computing an explicit function. The only known…

Quantum Physics · Physics 2007-05-23 Vwani P. Roychowdhury , Farrokh Vatan

This paper serves as a preparation of work that focuses on extracting cosmological sectors from Loop Quantum Gravity. We start with studying the extraction of subsystems from classical systems. A classical Hamiltonian system can be reduced…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Tim Koslowski

We formulate quantum mechanics in spacetimes with real-order fractional geometry and more general factorizable measures. In spacetimes where coordinates and momenta span the whole real line, Heisenberg's principle is proven and the…

High Energy Physics - Theory · Physics 2012-10-18 Gianluca Calcagni , Giuseppe Nardelli , Marco Scalisi

We propose introducing an extended Hubbard Hamiltonian derived via the ab initio downfolding method, which was originally formulated for periodic materials, towards efficient quantum computing of molecular electronic structure calculations.…

Quantum Physics · Physics 2024-08-29 Yuichiro Yoshida , Nayuta Takemori , Wataru Mizukami

We propose several designs to simulate quantum many-body systems in manifolds with a non-trivial topology. The key idea is to create a synthetic lattice combining real-space and internal degrees of freedom via a suitable use of induced…

It is commonly assumed that quantum field theory arises by applying ordinary quantum mechanics to the low energy effective degrees of freedom of a more fundamental theory defined at ultra-high-energy/short-wavelength scales. We shall argue…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Stefan Hollands , Robert M. Wald

Typically, quantum mechanics is thought of as a linear theory with unitary evolution governed by the Schr\"odinger equation. While this is technically true and useful for a physicist, with regards to computation it is an unfortunately…

Quantum Physics · Physics 2018-04-20 Dax Enshan Koh , Murphy Yuezhen Niu , Theodore J. Yoder