# CHEM 740/7400-02/QIC 890 - Spin-based Quantum Information Processing

## Semester: Winter 2023

**Professor:**J.D. Baugh |

**Discipline:**Theoretical |

#### Description

This course is inspired by recent experimental advances in the field of solid-state quantum information processing (QIP), especially electron spin qubits realized in semiconductor nanostructures (“artificial atoms”). It begins by covering the fundamentals of spin and angular momentum, QIP, semiconductor physics, quantum transport, and quantum dots. The course aims to equip students to fully comprehend the research literature in the spin qubit and related fields.

**What is spin?**

- Stern-Gerlach experiment
- Theories of electron spin from Pauli to Dirac
- Quantum measurement
- Spinors, spin-statistics connection

**Spin physics**

- Angular momentum in quantum mechanics
- Spin interactions
- Dynamics
- NMR, ESR

**Quantum** **information processing**

- NMR QIP as a canonical example
- T1,T2, spin refocusing

**Semiconductor physics**

- Energy bands
- Electrical conduction, density of states
- Fermi-Dirac distribution
- Doping
- Transport characteristics

**Quantum** **transport**

- Landauer conductance; density of states in 1D, 2D, 3D
- Quantum Hall effect
- Localization, conductance fluctuations
- Resonant tunneling

**Quantum** **dots and spin qubits**

- Single and double dot transport
- Pauli spin blockade
- Spin qubits in QDs
- Donor qubits
- Survey of recent advances

#### Materials

No required text, but an undergraduate level knowledge of quantum mechanics is assumed. Lectures will generally be given on whiteboard. Later in the course, research papers will be chosen for assigned reading. The earlier parts will be based primarily on books and reviews. I will provide a useful set of notes on “Intro to QIP and quantum control”. Some relevant textbooks are:

Semiconductor Physics and Devices, 3rd ed., D. A. Neaman, McGraw-Hill (2003).

Quantum Transport: Introduction to Nanoscience, Y. V. Nazarov and Y. M. Blanter, Cambridge University Press (2009).

Electronic Transport in Mesoscopic Systems, S. Datta, Cambridge University Press (1995). Spin Dynamics: basics of nuclear magnetic resonance, M. H. Levitt, Wiley (2001).

#### Evaluation

Grades are based on solving assigned problems, participation in discussion/analysis/presentation of research papers, and a course project. There is no exam. The breakdown is roughly 1/3 homework, 1/3 course project, 1/3 participation and paper presentation.

**Homework**

I will write down selected problems during lectures. Solutions will be handed in within two weeks.

**Reading and discussion**

Students are expected to read the assigned research and review papers and to be able to discuss and/or present them in class. Each student will present at least one paper.

#### Lab/Project

Part of the course mark will be based on a project. There are two options: (1) Identify an interesting but manageable research problem related to the course material and solve it by the end of term; (2) pick a course-related topic and write a literature-review type summary (in either case, the topic needs my approval). You will hand in a clear and concise write-up, no more than a few pages (LaTex preferred).

#### Schedule

- Tue: 1:00 pm - 2:20 pm in QNC 1201
- Thu: 1:00 pm - 2:20 pm in QNC 1201