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Standard quantum mechanics relies on two distinct dynamical principles: unitary evolution and collapse. A mathematically self-contained variational framework is presented that replaces this dualism with a single principle, in which…

Quantum Physics · Physics 2026-03-18 Lance H. Carter

We have investigated experimentally the magnetoresistance of strongly asymmetric double-wells. The structures were prepared by inserting a thin Al$_{0.3}$Ga$_{0.7}$As barrier into the GaAs buffer layer of a standard modulation-doped…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Yu. Krupko , L. Smrcka , P. Vasek , P. Svoboda , M. Cukr , L. Jansen

We report new experimental data on the plateau-insulator transition in the quantum Hall regime, taken from a low mobility InGaAs/InP heterostructure. By employing the fundamental symmetries of the quantum transport problem we are able to…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 A. M. M. Pruisken , D. T. N. de Lang , L. A. Ponomarenko , A. de Visser

A quasi-unidimensional one-electron double quantum dot is studied within the framework of Shannon informational entropy. Its confinement potential, which is described by an asymmetric harmonic-gaussian function, consists of two wells…

Atomic Physics · Physics 2024-12-30 W. S. Nascimento , A. M. Maniero , F. V. Prudente , C. R. de Carvalho , Ginette Jalbert

Continuous quantum metrology holds promise for realizing high-precision sensing by harnessing information progressively carried away by the radiation quanta emitted into the environment. Despite recent progress, a comprehensive…

Quantum Physics · Physics 2026-01-21 Kazuki Yokomizo , Aashish A. Clerk , Yuto Ashida

A pseudo-Hermitian coupled-channel square-well model is proposed, solved and discussed. The domain of parameters is determined where all the bound-state energies (twice degenerate with respect to the second observable which we call "spin")…

Quantum Physics · Physics 2007-05-23 Miloslav Znojil

Information-theoretical concepts are employed for the analysis of the interplay between a transverse electric field $\mathscr{E}$ applied to a one-dimensional surface and Robin boundary condition (BC), which with the help of the…

Quantum Physics · Physics 2017-04-26 O. Olendski

By using a point canonical transformation starting from the constant-mass Schr\"odinger equation for the Morse potential, it is shown that a semi-infinite quantum well model with a non-rectangular profile associated with a…

Quantum Physics · Physics 2023-05-04 C. Quesne

Nonlinear quantum metrology schemes can lead to faster than Heisenberg limited scalings for the measurement uncertainty. We study a Michelson interferometer embedded in a Kerr medium [Luis and Rivas, Phys. Rev. A 92, 022104 (2015)] that…

Quantum Physics · Physics 2021-12-07 Bijoy John Mathew , Anil Shaji

We present a protocol in which sequential weak measurements of a quantum harmonic oscillator enable simultaneous estimation of both quadratures of a displacement channel. Calculations of the quantum Fisher information show that the…

Quantum Physics · Physics 2026-05-04 Koray Mentesoglu , Rahul Trivedi , Sara Mouradian

For a wide variety of quantum potentials, including the textbook `instanton' examples of the periodic cosine and symmetric double-well potentials, the perturbative data coming from fluctuations about the vacuum saddle encodes all…

High Energy Physics - Theory · Physics 2017-06-23 Gokce Basar , Gerald V. Dunne , Mithat Unsal

The existence of incompatible measurements is a fundamental phenomenon having no explanation in classical physics. Intuitively, one considers given measurements to be incompatible within a framework of a physical theory, if their…

Quantum Physics · Physics 2015-08-27 Teiko Heinosaari , Jukka Kiukas , Daniel Reitzner

In multiparameter quantum metrology, the weighted-arithmetic-mean error of estimation is often used as a scalar cost function to be minimized during design optimization. However, other types of mean error can reveal different facets of…

Quantum Physics · Physics 2020-02-12 Xiao-Ming Lu , Zhihao Ma , Chengjie Zhang

The aim of the manuscript is to characterize monotone `metric' in the space of Markov map. Here, `metric' means the square of the norm defined on the tangent space, and not necessarily induced from an inner product (this property hereafter…

Quantum Physics · Physics 2010-02-01 Keiji Matsumoto

Quantum machine learning (QML) based on Noisy Intermediate-Scale Quantum (NISQ) devices hinges on the optimal utilization of limited quantum resources. While gate-based QML models are user-friendly for software engineers, their expressivity…

Quantum Physics · Physics 2024-06-27 Han-Xiao Tao , Jiaqi Hu , Re-Bing Wu

The well known metrological linear squeezing parameters (such as quadrature or spin squeezing) efficiently quantify the sensitivity of Gaussian states. Yet, these parameters are insufficient to characterize the much wider class of highly…

Quantum Physics · Physics 2019-03-11 Manuel Gessner , Augusto Smerzi , Luca Pezzè

We demonstrate that quantum Fisher information and superradiance can be formulated as coherence measures in accordance with the resource theory of coherence, thus establishing a direct link between metrological information, superradiance…

Quantum Physics · Physics 2018-05-09 Kok Chuan Tan , Seongjeon Choi , Hyukjoon Kwon , Hyunseok Jeong

We argue that it is possible in principle to reduce the uncertainty of an atomic magnetometer by double-passing a far-detuned laser field through the atomic sample as it undergoes Larmor precession. Numerical simulations of the quantum…

Quantum Physics · Physics 2009-06-17 Bradley A. Chase , Ben Q. Baragiola , Heather L. Partner , Brigette D. Black , JM Geremia

We consider the joint problem of system identification and inverse optimal control for discrete-time stochastic Linear Quadratic Regulators. We analyze finite and infinite time horizons in a partially observed setting, where the state is…

Optimization and Control · Mathematics 2025-02-24 Victor Geadah , Juncal Arbelaiz , Harrison Ritz , Nathaniel D. Daw , Jonathan D. Cohen , Jonathan W. Pillow

In this article, we study scaling laws for singularly perturbed two-well energies with prescribed Dirichlet boundary data in settings where the wells and/or the boundary data are incompatible. Our main focus is the geometrically linear…

Analysis of PDEs · Mathematics 2025-12-16 Noah Piemontese-Fischer