English
Related papers

Related papers: Unitary dynamics for quantum codewords

200 papers

Quantum entanglement plays an important role in quantum computation and communication. It is necessary for many protocols and computations, but causes unexpected disturbance of computational states. Hence, static analysis of quantum…

Quantum Physics · Physics 2015-11-06 Kentaro Honda

We present a quantum error correcting code with dynamically generated logical qubits. When viewed as a subsystem code, the code has no logical qubits. Nevertheless, our measurement patterns generate logical qubits, allowing the code to act…

Quantum Physics · Physics 2021-10-20 Matthew B. Hastings , Jeongwan Haah

We propose a quantum algorithm which uses the number of qubits in an optimal way and efficiently simulates a physical model with rich and complex dynamics described by the quantum sawtooth map. The numerical study of the effect of static…

Quantum Physics · Physics 2007-05-23 Giuliano Benenti , Giulio Casati , Simone Montangero , Dima L. Shepelyansky

Randomness is both a useful way to model natural systems and a useful tool for engineered systems, e.g. in computation, communication and control. Fully random transformations require exponential time for either classical or quantum…

Quantum Physics · Physics 2016-05-04 Fernando G. S. L. Brandao , Aram W. Harrow , Michal Horodecki

Quantum circuits -- built from local unitary gates and local measurements -- are a new playground for quantum many-body physics and a tractable setting to explore universal collective phenomena far-from-equilibrium. These models have shed…

Quantum Physics · Physics 2024-01-12 Matthew P. A. Fisher , Vedika Khemani , Adam Nahum , Sagar Vijay

The logic which describes quantum robots is not orthodox quantum logic, but a deductive calculus which reproduces the quantum tasks (computational processes, and actions) taking into account quantum superposition and quantum entanglement. A…

Quantum Physics · Physics 2009-05-28 Paola Zizzi

Nature provides us with a restricted set of microscopic interactions. The question is whether we can synthesize out of these fundamental interactions an arbitrary unitary operator. In this paper we present a constructive algorithm for…

Quantum Physics · Physics 2009-10-31 B. Hladky , G. Drobny , V. Buzek

Noise poses a challenge for any real-world implementation in quantum information science. The theory of quantum error correction deals with this problem via methods to encode and recover quantum information in a way that is resilient…

Quantum Physics · Physics 2009-09-10 Kurt M. Schreiter , Aron Pasieka , Rainer Kaltenbaek , Kevin J. Resch , David W. Kribs

Quantum dynamics can be driven by measurement. By constructing measurements that gain no information, effective unitary evolution can be induced on a quantum system, for example in ancilla driven quantum computation. In the non-ideal case…

Quantum Physics · Physics 2015-06-19 Daniel K. L. Oi

Simulating open quantum systems on quantum computers presents a fundamental challenge: open quantum dynamics are intrinsically nonunitary, whereas quantum computers operate through unitary evolution. Conventional approaches overcome this…

Quantum Physics · Physics 2025-10-27 Sameer Dambal , Akira Sone , Yu Zhang

The dynamics is investigated of a free particle on a sphere (rigid rotor or rotator) that is initially in a coherent state. The instability of coherent states with respect to the free evolution leads to nontrivial time-development of…

Quantum Physics · Physics 2013-09-24 K. Kowalski , J. Rembieliński

Quantum simulation has begun to penetrate the field of quantum chemistry in hopes of efficiently calculating ground state energies and approximating real-time evolution. With modern research highlighting nonadiabatic dynamics, tunably…

Quantum Physics · Physics 2026-05-08 Joshua M. Courtney , P. C. Stancil

Quantum Error Correction will be necessary for preserving coherent states against noise and other unwanted interactions in quantum computation and communication. We develop a general theory of quantum error correction based on encoding…

Quantum Physics · Physics 2009-01-23 Emanuel Knill , Raymond Laflamme

Proposals for quantum computing devices are many and varied. They each have unique noise processes that make none of them fully reliable at this time. There are several error correction/avoidance techniques which are valuable for reducing…

Quantum Physics · Physics 2015-06-26 Mark S. Byrd , Daniel A. Lidar

A successful quantum error correction protocol would allow quantum computers to run algorithms without suffering from the effects of noise. However, fully fault-tolerant quantum error correction is too resource intensive for existing…

Quantum Physics · Physics 2024-07-29 Chris N. Self , Marcello Benedetti , David Amaro

We present a logical calculus for reasoning about information flow in quantum programs. In particular we introduce a dynamic logic that is capable of dealing with quantum measurements, unitary evolutions and entanglements in compound…

Quantum Physics · Physics 2021-09-15 Alexandru Baltag , Sonja Smets

Using a quantumlike description for light propagation in nonhomogeneous optical fibers, quantum information processing can be implemented by optical means. Quantum-like bits (qulbits) are associated to light modes in the optical fiber and…

Quantum Physics · Physics 2009-11-07 M. A. Man'ko , V. I. Man'ko , R. Vilela Mendes

We describe a quantum error correction scheme aimed at protecting a flow of quantum information over long distance communication. It is largely inspired by the theory of classical convolutional codes which are used in similar circumstances…

Quantum Physics · Physics 2009-11-10 H. Ollivier , J. -P. Tillich

Although the conditions for performing arbitrary unitary operations to simulate the dynamics of a closed quantum system are well understood, the same is not true of the more general class of quantum operations (also known as superoperators)…

Quantum Physics · Physics 2007-05-23 Dave Bacon , Andrew M. Childs , Isaac L. Chuang , Julia Kempe , Debbie W. Leung , Xinlan Zhou

As quantum computers and simulators begin to produce results that cannot be verified classically, it becomes imperative to develop a variety of tools to detect and diagnose experimental errors on these devices. While state or process…

Quantum Physics · Physics 2022-12-22 Alaina M. Green , Tanmoy Pandit , C. Huerta Alderete , Norbert M. Linke , Raam Uzdin