Features and Applications of Random Unitaries

Random unitary model plays essential roles in the study of many-body quantum systems, and have many applications in the field of quantum information. In this thesis we will explore some features and applications of this model. We will first study the scrambling property of random circuits (i.e., seq...

Full description

Bibliographic Details
Main Author: Kong, Linghang
Other Authors: Harrow, Aram
Format: Thesis
Published: Massachusetts Institute of Technology 2022
Online Access:https://hdl.handle.net/1721.1/143199
_version_ 1811070751744196608
author Kong, Linghang
author2 Harrow, Aram
author_facet Harrow, Aram
Kong, Linghang
author_sort Kong, Linghang
collection MIT
description Random unitary model plays essential roles in the study of many-body quantum systems, and have many applications in the field of quantum information. In this thesis we will explore some features and applications of this model. We will first study the scrambling property of random circuits (i.e., sequential applications of random unitaries according to some interaction geometry). We will analyze the behaviors of two commonly used measures of scrambling, out-of-time-ordered correlation and entanglement, and show that the corresponding notions of scrambling can be fundamentally different. Then we will study one application of random unitaries, which is generation of near-optimal covariant quantum error-correcting codes (i.e., codes that obey some symmetry). We will show that quantum codes with U(1) and SU(d) symmetry could be generated using random unitaries with the corresponding symmetry, and the error rates of such codes typically saturate the fundamental limits. Finally, we will explore another application of random unitaries, the randomized benchmarking protocol. We will extend the randomized benchmarking framework in previous work to the setting of a continuous gate set. This allows us to benchmark arbitrary quantum gates in a unified way, which accommodates the need posed by experiments.
first_indexed 2024-09-23T08:41:00Z
format Thesis
id mit-1721.1/143199
institution Massachusetts Institute of Technology
last_indexed 2024-09-23T08:41:00Z
publishDate 2022
publisher Massachusetts Institute of Technology
record_format dspace
spelling mit-1721.1/1431992022-06-16T03:54:33Z Features and Applications of Random Unitaries Kong, Linghang Harrow, Aram Massachusetts Institute of Technology. Department of Physics Random unitary model plays essential roles in the study of many-body quantum systems, and have many applications in the field of quantum information. In this thesis we will explore some features and applications of this model. We will first study the scrambling property of random circuits (i.e., sequential applications of random unitaries according to some interaction geometry). We will analyze the behaviors of two commonly used measures of scrambling, out-of-time-ordered correlation and entanglement, and show that the corresponding notions of scrambling can be fundamentally different. Then we will study one application of random unitaries, which is generation of near-optimal covariant quantum error-correcting codes (i.e., codes that obey some symmetry). We will show that quantum codes with U(1) and SU(d) symmetry could be generated using random unitaries with the corresponding symmetry, and the error rates of such codes typically saturate the fundamental limits. Finally, we will explore another application of random unitaries, the randomized benchmarking protocol. We will extend the randomized benchmarking framework in previous work to the setting of a continuous gate set. This allows us to benchmark arbitrary quantum gates in a unified way, which accommodates the need posed by experiments. Ph.D. 2022-06-15T13:03:00Z 2022-06-15T13:03:00Z 2022-02 2022-05-25T22:43:40.482Z Thesis https://hdl.handle.net/1721.1/143199 0000-0002-5854-5340 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Kong, Linghang
Features and Applications of Random Unitaries
title Features and Applications of Random Unitaries
title_full Features and Applications of Random Unitaries
title_fullStr Features and Applications of Random Unitaries
title_full_unstemmed Features and Applications of Random Unitaries
title_short Features and Applications of Random Unitaries
title_sort features and applications of random unitaries
url https://hdl.handle.net/1721.1/143199
work_keys_str_mv AT konglinghang featuresandapplicationsofrandomunitaries