Part 4 Quantum LDPC codes | Nicolas Delfosse (Microsoft Research)
Channel: IAS | Park City Mathematics Institute | PCMI
Date: 2023-07-28

Lecture 4 notes
https://www.ias.edu/sites/default/files/Delfosse%20Lecture%204.pdf
Problem session 4
https://www.ias.edu/sites/default/files/Delfosse%20Problem%20Set%204.pdf
The surface code is the most popular quantum error code for the design of a large-scale fault-tolerant quantum computer but it leads to a huge overhead because each logical qubit is encoded into thousands of physical qubits. This course is about quantum Low-Density Parity-Check (LDPC) codes which is a class of quantum error correction codes that promises to reduce the overhead for fault-tolerant quantum computation. We will first review the necessary background on quantum error correction. Then, we will discuss different constructions of quantum LDPC codes, their decoding algorithms and their syndrome extraction circuits. 

--
The 2023 Program: Quantum Computation
Organizers: David Gosset, University of Waterloo; Aram Harrow, MIT; Stacey Jeffery, CWI and QuSoft; Ryan O'Donnell, Carnegie Mellon University; and Thomas Vidick, Caltech
Very recently we have seen experiments at the boundary of the "quantum computing advantage", where quantum computers can massively outperform classical ones at certain tasks.  These advances highlight the need for further mathematical understanding of the computational power of near-term quantum devices.  The goal of the 2023 GSS is to dive deeply into the mathematics relevant for building near-term quantum computers, analyzing their power, and putting them to use.  Minicourses will include: overviews of quantum learning, information theory, and linear-algebraic algorithms; recent advances in quantum error-correcting codes; and, the complexity theory of random circuits and Hamiltonians.

Structure:
The Graduate Summer School at PCMI consists of a series of several interwoven minicourses on different aspects of the main research theme of that summer.  These courses are taught by leading experts in the field, chosen not only for their stature in the field but their pedagogical abilities. Each minicourse comprises three to five lectures. Each course is accompanied by a daily problem session, structured to help students develop facility with the material.

2023 Schedule
Week 1 
  Andras: Quantum Fourier transform beyond Shor's algorithm
  Omar: Quantum information theory
  Srinivasan: Overview of quantum learning theory
Week 2 
  Ewin: Quantum and quantum-inspired linear algebra
  Nicolas: Quantum LDPC codes
  Yassine: Quantum query complexity
Week 3 
  Bill: Computational complexity of near-term quantum experiments
  Jeongwan: Topological aspects of quantum codes
  Sandy: Quantum Hamiltonian complexity
—
The GSS takes place within the broader structure of PCMI, so there are many researchers at all levels in the field in attendance, as well as participants in the other PCMI programs.

ias.edu/PCMI