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Related papers: Quantum sensing with a single-qubit pseudo-Hermiti…

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Many quantum algorithms rely on the measurement of complex quantum amplitudes. Standard approaches to obtain the phase information, such as the Hadamard test, give rise to large overheads due to the need for global controlled-unitary…

Quantum Physics · Physics 2024-05-29 Yilun Yang , Arthur Christianen , Mari Carmen Bañuls , Dominik S. Wild , J. Ignacio Cirac

We analyze the operation of a novel sensor based on atom interferometry, which can achieve supra-classical sensitivity by exploiting quantum correlations in mixed states of many qubits. The interferometer is based on quantum gates which use…

Quantum Physics · Physics 2016-02-05 Calum MacCormick , Silvia Bergamini , Chris Mansell , Hugo Cable , Kavan Modi

The Hermiticity axiom of quantum mechanics guarantees that the energy spectrum is real and the time evolution is unitary (probability-preserving). Nevertheless, non-Hermitian but $\mathcal{PT}$-symmetric Hamiltonians may also have real…

Quantum Physics · Physics 2018-06-06 Fernando Quijandría , Uta Naether , Sahin K. Özdemir , Franco Nori , David Zueco

We propose an approach to measuring nonresonant coupled systems, which gives a parametrically smaller error than the conventional fast projective measurements. The approach takes into account that, due to the coupling, excitations are not…

Quantum Physics · Physics 2009-03-05 L. Fedichkin , M. Shapiro , M. I. Dykman

Despite rapid advances in quantum hardware, noise remains a central obstacle to deploying quantum algorithms on near-term devices. In particular, random coherent errors that accumulate during circuit execution constitute a dominant and…

Quantum Physics · Physics 2026-01-29 Suying Liu , Yulong Dong , Dong An , Murphy Yuezhen Niu

Ever since the formulation of quantum mechanics, there is very little understanding of the process of the collapse of a wavefunction. We have proposed a dynamical model to emulate the measurement postulates of quantum mechanics. We…

Quantum Physics · Physics 2023-08-16 Gurpahul Singh , Ritesh K. Singh , Soumitro Banerjee

Higher-dimensional quantum systems (qudits) offer advantages in information encoding, error resilience, and compact gate implementations, and naturally arise in platforms such as superconducting and solid-state systems. However, realistic…

Quantum Physics · Physics 2025-06-17 Yule Mayevsky , Akram Youssry , Ritik Sareen , Gerardo A. Paz-Silva , Alberto Peruzzo

The performance of a quantum sensor is fundamentally limited by noise. This noise is particularly damaging when it becomes correlated with the readout of a target signal, caused by fluctuations of the sensor's operating parameters. These…

Pushing the boundaries of measurement precision is central for sensing and metrology, pursued by nonclassical resources such as squeezing, and non-Hermitian degeneracies with distinct spectral response. Their convergence, however, remains…

In this paper we present a model exhibiting a new type of continuous-time quantum walk (as a quantum mechanical transport process) on networks, which is described by a non-Hermitian Hamiltonian possessing a real spectrum. We call it…

Quantum Physics · Physics 2015-05-13 S. Salimi , A. Sorouri

Quantum parameter estimation with Hermitian systems has been applied in various fields, but there are relatively few results concerning non-Hermitian systems. Here, we study the quantum parameter estimation for general non-Hermitian…

Quantum Physics · Physics 2023-09-06 Xinglei Yu , Chengjie Zhang

We investigate the dynamics of a quantum system coupled linearly to Gaussian white noise using functional methods. By performing the integration over the noisy field in the evolution operator, we get an equivalent non-Hermitian Hamiltonian,…

Quantum Physics · Physics 2016-07-20 O. Oliveira , W. de Paula , T. Frederico , M. S. Hussein

We introduce the concept of furtive quantum sensing, demonstrating the possibility of concealing quantum objects from matter-waves, while maintaining their ability to interact and get excited by the impinging particles. This is obtained by…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Romain Fleury , Andrea Alu

Quantum sensors outperform their classical counterparts in their estimation precision, given the same amount of resources. So far, quantum-enhanced sensitivity has been achieved by exploiting the superposition principle. This enhancement…

Quantum Physics · Physics 2022-10-05 Victor Montenegro , Gareth Siôn Jones , Sougato Bose , Abolfazl Bayat

Quantum enhanced sensing provides a powerful tool for the precise measurement of physical parameters that is applicable in many areas of science and technology. The achievable gain in sensitivity is largely limited by the influence of noise…

Quantum Physics · Physics 2016-12-07 Yu Liu , Zijun Shu , Martin B. Plenio , Jianming Cai

Quantum computational sensing (QCS) combines quantum sensing with quantum computing to extract task-relevant information from the physical world. QCS can in principle achieve an accuracy advantage for specific tasks versus the alternative…

Quantum error mitigation (QEM) has emerged as a powerful tool for the extraction of useful quantum information from quantum devices. Here, we introduce the Subspace Noise Tailoring (SNT) algorithm, which efficiently combines the cheap cost…

Quantum information has been drawing a wealth of research in recent years, shedding light on questions at the heart of quantum mechanics, as well as advancing fields such as complexity theory, cryptography, key distribution, and chemistry.…

Quantum Physics · Physics 2017-04-25 Dikla Oren , Maor Mutzafi , Yonina C. Eldar , Mordechai Segev

We present an approach based on a non-Hermitian Hamiltonian to describe the process of measurement by tunneling of a phase qubit state. We derive simple analytical expressions which describe the dynamics of measurement, and compare our…

Quantum Physics · Physics 2012-11-15 Alexander I. Nesterov , Gennady P. Berman , Alan R. Bishop

A symmetric measure of quantum correlation based on the Hilbert-Schmidt distance is presented in this paper. For two-qubit states, we simplify considerably the optimization procedure so that numerical evaluation can be performed…

Quantum Physics · Physics 2011-07-18 Mingjun Shi , Fengjian Jiang , Jiangfeng Du