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Related papers: Quantum Metric Senses A Persistent Spin Helix

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We introduce the spin coherence scale as a measure of quantum coherence for spin systems, generalizing the quadrature coherence scale (QCS) previously defined for quadrature observables. This SU($2$)-invariant measure quantifies the…

Quantum Physics · Physics 2025-10-14 Aaron Z. Goldberg , Anaelle Hertz

The spin orbit interaction plays a crucial role in diverse fields of condensed matter, including the investigation of Majorana fermions, topological insulators, quantum information and spintronics. In III V zinc blende semiconductor…

Mesoscale and Nanoscale Physics · Physics 2014-08-25 A. Sasaki , S. Nonaka , Y. Kunihashi , M. Kohda , T. Bauernfeind , T. Dollinger , K. Richter , J. Nitta

We derive quantum geometric bounds in spinful systems with spin topology characterized by a single $\mathbb{Z}$ index protected by a spin gap. Our bounds provide geometric conditions on the spin topology, distinct from the known quantum…

Mesoscale and Nanoscale Physics · Physics 2025-10-13 Wojciech J. Jankowski , Robert-Jan Slager , Gunnar F. Lange

States of a quantum mechanical system are represented by rays in a complex Hilbert space. The space of rays has, naturally, the structure of a K\"ahler manifold. This leads to a geometrical formulation of the postulates of quantum mechanics…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Abhay Ashtekar , Troy A. Schilling

The use of geometric and symmetry techniques in quantum and classical information processing has a long tradition across the physical sciences as a means of theoretical discovery and applied problem solving. In the modern era, the emergent…

Quantum Physics · Physics 2024-09-10 Elija Perrier

We study the lifetime of the persistent spin helix in semiconductor quantum wells with equal Rashba- and linear Dresselhaus spin-orbit interactions. In order to address the temperature dependence of the relevant spin relaxation mechanisms…

Mesoscale and Nanoscale Physics · Physics 2013-02-19 Matthias C. Lüffe , Janik Kailasvuori , Tamara S. Nunner

According to Noethers theorem, for every symmetry in nature there is a corresponding conservation law. For example, invariance with respect to spatial translation corresponds to conservation of momentum. In another well-known example,…

Quantum metrology is a promising practical use case for quantum technologies, where physical quantities can be measured with unprecedented precision. In lieu of quantum error correction procedures, near term quantum devices are expected to…

Quantum Physics · Physics 2021-12-03 Yingkai Ouyang , Nathan Shettell , Damian Markham

The Rashba and Dresselhaus spin-orbit (SO) interactions in 2D electron gases act as effective magnetic fields with momentum-dependent directions, which cause spin decay as the spins undergo arbitrary precessions about these…

Mesoscale and Nanoscale Physics · Physics 2017-07-26 Florian Dettwiler , Jiyong Fu , Shawn Mack , Pirmin J. Weigele , J. Carlos Egues , David D. Awschalom , Dominik M. Zumbühl

We propose a geometric model predictive control framework for quantum systems subject to smoothness and state constraints. By formulating quantum state evolution intrinsically on the projective Hilbert space, we penalize covariant…

Mathematical Physics · Physics 2026-02-10 Leonardo Colombo

Symmetries are a key concept to connect mathematical elegance with physical insight. We consider measurement assemblages in quantum mechanics and show how their symmetry can be described by means of the so-called discrete bundles. It turns…

Quantum Physics · Physics 2020-03-30 H. Chau Nguyen , Sébastien Designolle , Mohamed Barakat , Otfried Gühne

We study the geometric measure of quantum coherence recently proposed in [Phys. Rev. Lett. 115, 020403 (2015)]. Both lower and upper bounds of this measure are provided. These bounds are shown to be tight for a class of important coherent…

Quantum Physics · Physics 2017-03-14 Hai-Jun Zhang , Bin Chen , Ming Li , Shao-Ming Fei , Gui-Lu Long

Spin textures of one or two electrons in a quantum dot with Rashba or Dresselhaus spin-orbit couplings reveal several intriguing properties. We show that even at the single-electron level spin vortices with different topological charges…

Mesoscale and Nanoscale Physics · Physics 2019-01-25 Wenchen Luo , Amin Naseri , Jesko Sirker , Tapash Chakraborty

We present a geometric formulation of quantum mechanics based on the symplectic structure of the projective Hilbert space. Building upon the standard K\"ahler framework, we introduce an extension in which the symplectic structure is allowed…

Quantum Physics · Physics 2026-03-25 Hoshang Heydari

The concept of fixed-area states has proven useful for recent studies of quantum gravity, especially in connection with gravitational holography. We explore the Lorentz-signature spacetime geometry intrinsic to such fixed-area states in…

High Energy Physics - Theory · Physics 2022-09-07 Xi Dong , Donald Marolf , Pratik Rath , Amirhossein Tajdini , Zhencheng Wang

The quantum metric, a geometric measure of state-space distance, has recently attracted growing attention for capturing anomalous state responses to parameter variations. Especially in non-Hermitian systems, the quantum metric has been…

Quantum Physics · Physics 2026-03-31 Teng Liu , Xiaohang Zhang , Jiawei Zhang , Le Luo

We investigate ramifications of the persistent spin helix symmetry in two-dimensional hole gases in the conductance of disordered mesoscopic systems. To this end we extend previous models by going beyond the axial approximation for III-V…

Mesoscale and Nanoscale Physics · Physics 2014-11-26 Tobias Dollinger , Michael Kammermeier , Andreas Scholz , Paul Wenk , R. Winkler , John Schliemann , Klaus Richter

Symmetries impose structure on the Hilbert space of a quantum mechanical model. The mathematical units of this structure are the irreducible representations of symmetry groups and I consider how they function as conceptual units of…

Quantum Physics · Physics 2018-01-29 N. L. Harshman

The quantum metric, a key component of quantum geometry, plays a central role in a wide range of physical phenomena and has been extensively studied in periodic crystals and moir\'{e} materials. Here, we systematically investigate quantum…

Mesoscale and Nanoscale Physics · Physics 2025-07-08 Jundi Wang , Yuxiao Chen , Huaqing Huang

Geometrical structures of quantum mechanics provide us with new insightful results about the nature of quantum theory. In this work we consider mixed quantum states represented by finite rank density operators. We review our geometrical…

Quantum Physics · Physics 2015-06-23 Hoshang Heydari , Ole Andersson