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Inspired by the discovery of a variety of correlated insulators in the moir\'e universe, controlled by interactions projected to a set of isolated bands with a narrow bandwidth, we examine here a partial sum-rule associated with the inverse…

Strongly Correlated Electrons · Physics 2025-08-12 Dan Mao , Juan Felipe Mendez-Valderrama , Debanjan Chowdhury

We study the dynamics of electrons in crystalline solids in the presence of inhomogeneous external electric and magnetic fields. We present a manifestly gauge-invariant operator-based approach without relying on a semiclassical wavepacket…

Mesoscale and Nanoscale Physics · Physics 2025-03-17 Chen Xu , Andreas Haller , Suraj Hegde , Tobias Meng , Thomas L. Schmidt

A generalized Bloch sphere, in which the states of a quantum entity of arbitrary dimension are geometrically represented, is investigated and further extended, to also incorporate the measurements. This extended representation constitutes a…

Quantum Physics · Physics 2015-12-16 Diederik Aerts , Massimiliano Sassoli de Bianchi

We employ a quantum Langevin equation approach to establish non-Markovian dynamical equations, on a fully microscopic basis, to investigate the measurement of the state of a coupled quantum dot qubit by a nearby quantum point contact. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Bing Dong , Norman J. M. Horing , X. L. Lei

Sum rules for linear response functions give powerful and experimentally-relevant relations between frequency moments of response functions and ground state properties. In particular, renewed interest has been drawn to optical conductivity…

Mesoscale and Nanoscale Physics · Physics 2025-03-19 Barry Bradlyn , Peter Abbamonte

The quantum geometric tensor (QGT) provides nontrivial bounds among physical quantities, as exemplified by the metric-curvature inequality. In this paper, we investigate various bounds for different observables through certain…

Materials Science · Physics 2025-10-28 Koki Shinada , Naoto Nagaosa

The generalized Bloch decomposition of a bipartite quantum state gives rise to a correlation matrix whose singular values provide rich information about non-local properties of the state, such as the dimensionality of entanglement. While…

Quantum Physics · Physics 2023-05-12 Nikolai Wyderka , Andreas Ketterer

Recently a model of metric fluctuations has been proposed which yields an effective Schr\"odinger equation for a quantum particle with a modified inertial mass, leading to a violation of the weak equivalence principle. The renormalization…

General Relativity and Quantum Cosmology · Physics 2015-06-26 H. -P. Breuer , E. Göklü , C. Lämmerzahl

We show how the effects of large numbers of measurements on many-body quantum ground and thermal states can be studied using Quantum Monte Carlo (QMC). Density matrices generated by measurement in this setting feature products of many local…

Statistical Mechanics · Physics 2026-05-12 Kriti Baweja , David J. Luitz , Samuel J. Garratt

Low-capacitance Josephson junction systems as well as coupled quantum dots, in a parameter range where single charges can be controlled, provide physical realizations of quantum bits, discussed in connection with quantum computing. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alexander Shnirman , Gerd Schoen

The calculation of quantum-geometric properties of Bloch electrons -- Berry curvature, quantum metric, orbital magnetic moment and effective mass -- was implemented in a pseudopotential plane-wave code. The starting point was the first…

Materials Science · Physics 2025-10-29 José Luís Martins , Carlos Loia Reis , Ivo Souza

In quantum mechanics, measurements are dynamical processes and thus they should be capable of inducing currents. The symmetries of the Hamiltonian and measurement operator provide an organizing principle for understanding the conditions for…

Quantum Physics · Physics 2025-06-12 Luka Antonic , Yariv Kafri , Daniel Podolsky , Ari M. Turner

Quantum metrology utilizes entanglement for improving the sensitivity of measurements. Up to now the focus has been on the measurement of just one out of two non-commuting observables. Here we demonstrate a laser interferometer that…

Quantum geometry has been identified as an important ingredient for the physics of quantum materials and especially of flat-band systems, such as moir\'e materials. On the other hand, the coupling between light and matter is of key…

Optics · Physics 2021-08-25 G. E. Topp , C. J. Eckhardt , D. M. Kennes , M. A. Sentef , P. Törmä

The importance of the quantum metric in flat-band systems has been noticed recently in many contexts such as the superfluid stiffness, the dc electrical conductivity, and ideal Chern insulators. Both the quantum metric of degenerate and…

Mesoscale and Nanoscale Physics · Physics 2022-11-10 Bruno Mera , Johannes Mitscherling

With the help of quantum entanglement, quantum dense metrology (QDM) is a technique that can perform the joint estimates of two conjugate quantities such as phase and amplitude modulations of an optical field with an accuracy beating the…

Quantum Physics · Physics 2022-02-02 Wei Du , J. F. Chen , Z. Y. Ou , Weiping Zhang

Making use of coherence and entanglement as metrological quantum resources allows to improve the measurement precision from the shot-noise- or quantum limit to the Heisenberg limit. Quantum metrology then relies on the availability of…

Quantum metrology holds the promise of an early practical application of quantum technologies, in which measurements of physical quantities can be made with much greater precision than what is achievable with classical technologies. In this…

Quantum Physics · Physics 2021-01-27 Jasminder S. Sidhu , Pieter Kok

Quantum state space is endowed with a metric structure and Riemannian monotone metric is an important geometric entity defined on such a metric space. Riemannian monotone metrics are very useful for information-theoretic and statistical…

Quantum Physics · Physics 2016-04-12 Prasenjit Deb

We review some geometrical aspects pertaining to the world of monotone quantum metrics in finite dimensions. Particular emphasis is given to an unfolded perspective for quantum states that is built out of the spectral theorem and is…

Quantum Physics · Physics 2023-09-13 Florio M. Ciaglia , Fabio Di Cosmo , Fabio Di Nocera , Patrizia Vitale