# Quasi-exact quantum computation

@article{Wang2019QuasiexactQC, title={Quasi-exact quantum computation}, author={Dong-Sheng Wang and Guanyu Zhu and Cihan Okay and Raymond Laflamme}, journal={arXiv: Quantum Physics}, year={2019} }

We study quasi-exact quantum error correcting codes and quantum computation with them. A quasi-exact code is an approximate code such that it contains a finite number of scaling parameters, the tuning of which can flow it to corresponding exact codes, serving as its fixed points. We find that the incompatibility between universality and transversality of the set of quantum gates does not persist in the quasi-exact scenario. A class of covariant quasi-exact codes is defined which proves to…

## 10 Citations

A comparative study of universal quantum computing models: towards a physical unification

- Computer Science, PhysicsQuantum Eng.
- 2021

This work carried out a primary attempt to unify UQCM by classifying a few of them as two categories, hence making a table of models, which reveals the importance and feasibility of systematic study of computing models.

Theory of quasi-exact fault-tolerant quantum computing and valence-bond-solid codes

- Computer Science, PhysicsNew Journal of Physics
- 2021

This work develops quasi error-correction theory using quantum instrument, the notions of quasi universality, quasi code distances, and quasi thresholds, etc, and finds a wide class of quasi codes which are called valence-bond-solid codes, and uses them as concrete examples to demonstrate QEQ computation.

Near-Optimal Covariant Quantum Error-Correcting Codes from Random Unitaries with Symmetries

- PhysicsPRX Quantum
- 2022

The results not only indicate (potentially eﬃcient) randomized constructions of optimal U (1)- and SU ( d )-covariant codes, but also reveal fundamental properties of random symmetric unitaries, which yield important solvable models of complex quantum systems that have attracted great recent interest in quantum gravity and condensed matter physics.

Optimal universal quantum error correction via bounded reference frames

- PhysicsPhysical Review Research
- 2022

Yuxiang Yang,1, 2 Yin Mo,2 Joseph M. Renes,1 Giulio Chiribella,2, 3, 4, 5 and Mischa P. Woods1 Institute for Theoretical Physics, ETH Zürich, Switzerland QICI Quantum Information and Computation…

A prototypical model of universal quantum computer system

- Computer Science, PhysicsArXiv
- 2021

A model of universal quantum computer system, the quantum version of the von Neumann architecture is proposed, which demonstrates the manifold power of quantum information and paves the way for the creation of quantum computer systems in the near future.

New perspectives on covariant quantum error correction

- Physics, Computer ScienceQuantum
- 2021

New and powerful lower bounds on the infidelity of covariant quantum error correction are proved, which not only extend the scope of previous no-go results but also provide a substantial improvement over existing bounds.

Quantum error correction meets continuous symmetries: fundamental trade-offs and case studies

- Computer Science
- 2021

Borders on symmetry violation indicate limitations on the precision or density of transversally implementable logical gates for general QEC codes, reﬁning the Eastin–Knill theorem and nontrivial approximately covariant codes.

Using Quantum Metrological Bounds in Quantum Error Correction: A Simple Proof of the Approximate Eastin-Knill Theorem.

- PhysicsPhysical review letters
- 2021

We present a simple proof of the approximate Eastin-Knill theorem, which connects the quality of a quantum error-correcting code (QECC) with its ability to achieve a universal set of transversal…

Classes of topological qubits from low-dimensional quantum spin systems

- PhysicsAnnals of Physics
- 2020

Error Correction of Quantum Reference Frame Information

- Computer Science
- 2017

A no-go theorem is proved showing that that no finite dimensional, group-covariant quantum codes exist for Lie groups with an infinitesimal generator, and it is demonstrated that all finite groups have finite dimensional codes.

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