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We show that the interaction constant governing the long-range electron-electron interaction in a quantum wire coupled to two reservoirs and capacitively coupled to a gate can be determined by a low frequency measurement. We present a…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Ya. M. Blanter , F. W. J. Hekking , M. Buttiker

Randomized benchmarking is a powerful technique to efficiently estimate the performance and reliability of quantum gates, circuits and devices. Here we propose to perform randomized benchmarking in a coherent way, where superpositions of…

Quantum Physics · Physics 2021-07-14 Jorge Miguel-Ramiro , Alexander Pirker , Wolfgang Dür

Gradient-based optimization is a key ingredient of variational quantum algorithms, with applications ranging from quantum machine learning to quantum chemistry and simulation. The parameter-shift rule provides a hardware-friendly method for…

Quantum Physics · Physics 2025-10-08 Leonardo Banchi , Dominic Branford , Chetan Waghela

Pseudorandom circuits generate quantum states and unitary operators which are approximately distributed according to the unitarily invariant Haar measure. We explore how several design parameters affect the efficiency of pseudo-random…

Quantum Physics · Physics 2009-11-13 Yaakov S. Weinstein , Winton G. Brown , Lorenza Viola

Randomness is an indispensable resource in modern science and information technology. Fortunately, an experimentally simple procedure exists to generate randomness with well-characterized devices: measuring a quantum system in a basis…

Quantum Physics · Physics 2016-08-24 Le Phuc Thinh , Jean-Daniel Bancal , Eduardo Martin-Martinez

A systematic theory of the conductance measurements of non-invasive (weak probe) scanning gate microscopy is presented that provides an interpretation of what precisely is being measured. A scattering approach is used to derive explicit…

Mesoscale and Nanoscale Physics · Physics 2013-07-12 C. Gorini , R. A. Jalabert , W. Szewc , S. Tomsovic , D. Weinmann

Parameterized quantum circuits have been extensively used as the basis for machine learning models in regression, classification, and generative tasks. For supervised learning, their expressivity has been thoroughly investigated and several…

Quantum Physics · Physics 2026-05-20 Alice Barthe , Michele Grossi , Sofia Vallecorsa , Jordi Tura , Vedran Dunjko

The evolution of a quantum system undergoing repeated indirect measurements naturally leads to a Markov chain on the set of states which is called a quantum trajectory. In this paper we consider a specific model of such a quantum trajectory…

Mathematical Physics · Physics 2025-10-22 Tristan Benoist , Laurent Bruneau , Clément Pellegrini

The conductance distribution of metallic mesoscopic systems is considered. The variance of this distribution describes the universal conductance fluctuations, yielding a Gaussian distribution of the conductance. We calculate…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 M. C. W. van Rossum , Igor V. Lerner , Boris L. Altshuler , Th. M. Nieuwenhuizen

We evaluate the covariance matrix of the matter power spectrum using perturbation theory up to dominant terms at 1-loop order and compare it to numerical simulations. We decompose the covariance matrix into the disconnected (Gaussian) part,…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Irshad Mohammed , Uros Seljak , Zvonimir Vlah

Heisenberg's uncertainty principle implies fundamental constraints on what properties of a quantum system can we simultaneously learn. However, it typically assumes that we probe these properties via measurements at a single point in time.…

Quantum Physics · Physics 2023-06-21 Yunlong Xiao , Yuxiang Yang , Ximing Wang , Qing Liu , Mile Gu

The conductance of disordered wires with symplectic symmetry is studied by a random-matrix approach. It has been believed that Anderson localization inevitably arises in ordinary disordered wires. A counterexample is recently found in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Hiroshi Sakai , Yositake Takane

Measurements with randomly chosen settings determine many important properties of quantum states without the need for a shared reference frame or calibration. They naturally emerge in the context of quantum communication and quantum…

One dimensional (1D) quantum wires exhibit a conductance feature near 0.7 x 2e^2/h in connection with many-body interactions involving the electron spin. With the possibility of exploiting this effect for novel spintronic device…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 D. J. Reilly

We investigate the asymptotic dynamics of quantum networks under repeated applications of random unitary operations. It is shown that in the asymptotic limit of large numbers of iterations this dynamics is generally governed by a typically…

Quantum Physics · Physics 2009-04-02 J. Novotny , G. Alber , I. Jex

While the size of functional elements in memristors becomes of the orders of nano-meters or even smaller, the quantum effects in their dynamics can significantly influence their transport properties, consistent with recent experimental…

Mesoscale and Nanoscale Physics · Physics 2023-03-22 C Huggins , S Savel'ev , A Balanov , A Zagoskin

A one-dimensional, two-channel quantum wire is studied in the effective non-Hermitian Hamiltonian framework. Analytical expressions are derived for the band structure of the isolated wire. Quantum states and transport properties of the wire…

Mesoscale and Nanoscale Physics · Physics 2016-01-27 Amin Tayebi , Vladimir Zelevinsky

We investigate quantum walks in multiple dimensions with different quantum coins. We augment the model by assuming that at each step the amplitudes of the coin state are multiplied by random phases. This model enables us to study in detail…

Quantum Physics · Physics 2009-11-13 Jozef Kosik , Vladimir Buzek , Mark Hillery

In this paper we introduce a simple procedure for computing the macroscopic quantum behaviour of periodic quantum systems in the high energy regime. The macroscopic quantum coherence is ascribed to a one-particle state, not to a condensate…

Quantum Physics · Physics 2015-06-17 A. Martín-Ruiz , J. Bernal , Adrián Carbajal-Domínguez

Covariance matrices of amino acid displacements, commonly used to characterize the large-scale movements of proteins, are investigated through the prism of Random Matrix Theory. Bulk universality is detected in the local spacing statistics…

Quantitative Methods · Quantitative Biology 2013-05-29 Raffaello Potestio , Fabio Caccioli , Pierpaolo Vivo