English
Related papers

Related papers: Structure, Optimality, and Symmetry in Shadow Unit…

200 papers

Unitary $k$-designs are distributions of unitary gates that match the Haar distribution up to its $k$-th statistical moment. They are a crucial resource for randomized quantum protocols. However, their implementation on encoded logical…

Quantum Physics · Physics 2025-08-25 Zihan Cheng , Eric Huang , Vedika Khemani , Michael J. Gullans , Matteo Ippoliti

In this paper, the space complexity of nonuniform quantum computations is investigated. The model chosen for this are quantum branching programs, which provide a graphic description of sequential quantum algorithms. In the first part of the…

Quantum Physics · Physics 2007-05-23 M. Sauerhoff , D. Sieling

Let $L_0$ be a closed densely defined symmetric semi-bounded operator with nonzero defect indexes in a separable Hilbert space ${\cal H}$. With $L_0$ we associate a metric space $\Omega_{L_0}$ that is named a {\it wave spectrum} and…

Functional Analysis · Mathematics 2010-04-13 M. I. Belishev

We experimentally demonstrate a weak measurement and measurement reversal-based scheme to ameliorate the effects of decoherence due to amplitude damping, on an NMR quantum processor. The weak measurement and measurement reversal processes…

Quantum Physics · Physics 2024-09-20 Gayatri Singh , Akshay Gaikwad , Arvind , Kavita Dorai

Based on a recent purely geometric construction of observables for the spatial diffeomorphism constraint, we propose two distinct quantum reductions to spherical symmetry within full 3+1-dimensional loop quantum gravity. The construction of…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Norbert Bodendorfer , Jerzy Lewandowski , Jedrzej Świeżewski

Traditional spatial queries return, for a given query object $q$, all database objects that satisfy a given predicate, such as epsilon range and $k$-nearest neighbors. This paper defines and studies {\em inverse} spatial queries, which,…

Shadow estimation is a recent protocol that allows estimating exponentially many expectation values of a quantum state from ``classical shadows'', obtained by applying random quantum circuits and computational basis measurements. In this…

Quantum Physics · Physics 2023-12-27 Jonas Helsen , Michael Walter

Variational algorithms require architectures that naturally constrain the optimization space to run efficiently. Geometric quantum machine learning achieves this goal by encoding group structure into parameterized quantum circuits to…

Quantum Physics · Physics 2026-03-25 Richard D. P. East , Guillermo Alonso-Linaje , Chae-Yeun Park

The fragile nature of quantum information limits our ability to construct large quantities of quantum bits suitable for quantum computing. An important goal, therefore, is to minimize the amount of resources required to implement quantum…

Quantum Physics · Physics 2013-04-11 Adam Paetznick , Austin G. Fowler

In this paper, we present a unified computational method based on pseudospectral approximations for the design of optimal pulse sequences in open quantum systems. The proposed method transforms the problem of optimal pulse design, which is…

Chemical Physics · Physics 2009-08-17 Jr-Shin Li , Justin Ruths , Dionisis Stefanatos

Quantum query complexity is a fundamental model for analyzing the computational power of quantum algorithms. It has played a key role in characterizing quantum speedups, from early breakthroughs such as Grover's and Simon's algorithms to…

Quantum Physics · Physics 2025-08-13 Yassine Hamoudi

Units equivariance (or units covariance) is the exact symmetry that follows from the requirement that relationships among measured quantities of physics relevance must obey self-consistent dimensional scalings. Here, we express this…

Machine Learning · Statistics 2023-06-26 Soledad Villar , Weichi Yao , David W. Hogg , Ben Blum-Smith , Bianca Dumitrascu

State-of-the-art quantum computers can only reliably execute circuits with limited qubit numbers and computational depth. This severely reduces the scope of algorithms that can be run. While numerous techniques have been invented to exploit…

Quantum Physics · Physics 2023-12-25 Adrián Pérez-Salinas , Radoica Draškić , Jordi Tura , Vedran Dunjko

This paper aims to implement and evaluate the performance of quantum computing on solving combinatorial optimization problems arising from the operations of the power grid. To this end, we construct a novel mixed integer conic programming…

Systems and Control · Electrical Eng. & Systems 2022-08-17 Phuong Ngo , Christan Thomas , Hieu Nguyen , Abdullah Eroglu , Konstantinos Oikonomou

Predicting properties of large-scale quantum systems is crucial for the development of quantum science and technology. Shadow estimation is an efficient method for this task based on randomized measurements, where many-qubit random Clifford…

Quantum Physics · Physics 2024-04-24 Qingyue Zhang , Qing Liu , You Zhou

Simultaneous optimization of multiple quantum objectives is often considered a demanding task. However, a special circumstance arises when a primary objective is pitted against a set of secondary objectives, which we show leads to invariant…

Quantum Physics · Physics 2015-07-22 David Hocker , Herschel Rabitz

A quantum gate is realized by specific unitary transformations operating on states representing qubits. Considering a quantum system employed as an element in a quantum computing scheme, the task is therefore to enforce the pre-specified…

Quantum Physics · Physics 2007-05-23 Jose P. Palao , Ronnie Kosloff

The standard quantum search algorithm lacks a feature, enjoyed by many classical algorithms, of having a fixed-point, i.e. a monotonic convergence towards the solution. Here we present two variations of the quantum search algorithm, which…

Quantum Physics · Physics 2007-05-23 Lov K. Grover , Apoorva Patel , Tathagat Tulsi

An optical waveplate rotating light polarization can be modeled as a single-qubit unitary operator, whose action can be experimentally determined via quantum process tomography. Standard approaches to tomographic problems rely on the…

Almost all of the most successful quantum algorithms discovered to date exploit the ability of the Fourier transform to recover subgroup structure of functions, especially periodicity. The fact that Fourier transforms can also be used to…

Quantum Physics · Physics 2007-05-23 Wim van Dam , Sean Hallgren , Lawrence Ip