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Quantum Science & Technologies - PHY00078H

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  • Department: Physics
  • Credit value: 20 credits
  • Credit level: H
  • Academic year of delivery: 2023-24
    • See module specification for other years: 2024-25

Module summary

The field of Quantum Science and Technologies has been expanding exponentially over the last two decades. In this module we will focus in particular on quantum computation and quantum communications. At the core of quantum computation is the idea of finding a physical system with the right characteristics to build the "quantum computer", a device which can improve computer performance to levels unreachable by standard (i.e. "classical") computers.

A quantum computer is based on the smallest possible quantum system (the two-level system or "quantum-bit") and on exquisite quantum mechanical properties, such as state superposition.There are proposals for quantum computers based on semiconductors, superconductors, cold ions or atoms, molecules in a solvent, photons and so on. Each of the proposals has advantages and disadvantages, and has been partially tested experimentally. The requirements to build a quantum computer are experimentally very challenging, so that the experiments performed in this area are at the very edge of modern techniques.

Quantum communications are the counterpart of quantum computers. Rather than building on the superposition properties of quantum states, they exploit the limiting principles of quantum mechanics, such as the no-cloning theorem, to enable novel and more secure ways to communicate. Quantum communications based on photons represent the first quantum technology reaching a maturity level suitable for the market. They find application in cybersecurity, which is threatened by the advent of quantum computers, and pave the way to exotic protocols for transferring information like quantum teleportation and superdense coding.

Related modules

Pre-requisites:  Stage 3 Quantum Mechanics 

 Prohibited Combinations: Maths Module on Quantum Computing

Module will run

Occurrence Teaching period
A Semester 2 2023-24

Module aims

This module aims to provide an introduction to the booming research fields of Quantum Computation and Quantum Communication, with some references to other quantum technologies.

Module learning outcomes

  • understand the fundamentals of quantum computation including the basics of quantum-error correction

  • understand the requirements for physical systems to be used as quantum computers

  • knowledge of some of the proposals for quantum computers including overviews of the related experimental methods.

  • understand the fundamentals of quantum communications, including some modern protocols for quantum communications

  • understand theoretical versus implementation of security

  • knowledge of some quantum key distribution methods

Module content

  • Fundamentals of quantum computation:

  • concept of quantum bit (qubit);

  • concept of basis set

  • examples of physical systems used as qubits;

  • Bloch sphere and single qubit representation

  • single qubit gates

  • Pauli matrices

  • circuit representation of single qubit gates

  • two qubit states: Dirac and vectorial representation

  • two qubit gates and their matrix representation

  • tensor product between qubit gates and between qubit states

  • circuit representation of two qubit gates

  • role of superposition principle (quantum parallelism);

  • concept of entanglement; differentiating between entangled and non-entangled states

  • Bell states; EPR paradox and Bell inequality; significance of Bell inequality for Quantum Mechanics

  • Concept of teleportation; teleportation protocol for one qubit

  • quantum circuits

  • hints to improvements of quantum over standard 'classical' computation and problem complexity

  • concept of density matrix and its properties; concept and differences between pure and mixed states

  • Concept of quantum error correction; three-qubit code error correction

  • Requirements for physical systems to be used as quantum computers: Di Vincenzo check list

  • physical systems proposed as quantum computers, e.g. ion trap quantum computer, quantum- dot-based quantum computer, silicon-based NMR quantum processor, liquid state NMR quantum processor

  • For each proposal: how two qubit gates translate into physical interactions; main physical limitations to quantum computation (decoherence and scalability)

  • Experiments related to specific proposals.

  • Generalities on one-way quantum computation

  • Limiting theorems of quantum mechanics: no-cloning and optimal cloning machine, information vs disturbance, shot-noise limited measurements

  • basic notions and protocols of quantum cryptography: binary entropy, Shannon theorem, BB84, B92 and E91 protocols

  • theoretical versus implementation security

  • continuous-variable quantum key distribution: gaussian modulation and coherent detection

  • quantum teleportation as a communication protocol and superdense coding

  • modern protocols for quantum communications: measurement device independent, device independent and twin field quantum key distribution

  • Bell inequalities enabling super secure communications

Indicative assessment

Task % of module mark
Closed/in-person Exam (Centrally scheduled) 80
Essay/coursework 20

Special assessment rules

Non-reassessable

Indicative reassessment

Task % of module mark
Closed/in-person Exam (Centrally scheduled) 80

Module feedback

'Feedback’ at a university level can be understood as any part of the learning process which is designed to guide your progress through your degree programme. We aim to help you reflect on your own learning and help you feel more clear about your progress through clarifying what is expected of you in both formative and summative assessments.

A comprehensive guide to feedback and to forms of feedback is available in the Guide to Assessment Standards, Marking and Feedback. This can be found at:

https://www.york.ac.uk/students/studying/assessment-and-examination/guide-to-assessment/

The School of Physics, Engineering & Technology aims to provide some form of feedback on all formative and summative assessments that are carried out during the degree programme. In general, feedback on any written work/assignments undertaken will be sufficient so as to indicate the nature of the changes needed in order to improve the work. Students are provided with their examination results within 25 working days of the end of any given examination period. The School will also endeavour to return all coursework feedback within 25 working days of the submission deadline. The School would normally expect to adhere to the times given, however, it is possible that exceptional circumstances may delay feedback. The School will endeavour to keep such delays to a minimum. Please note that any marks released are subject to ratification by the Board of Examiners and Senate. Meetings at the start/end of each semester provide you with an opportunity to discuss and reflect with your supervisor on your overall performance to date.

Our policy on how you receive feedback for formative and summative purposes is contained in our Physics at York Taught Student Handbook.

Indicative reading

  • Articles from literature

  • M.A. Nielsen and I. L. Chuang: Quantum Computation and Quantum Information (Cambridge University Press)


The information on this page is indicative of the module that is currently on offer. The University constantly explores ways to enhance and improve its degree programmes and therefore reserves the right to make variations to the content and method of delivery of modules, and to discontinue modules, if such action is reasonably considered to be necessary. In some instances it may be appropriate for the University to notify and consult with affected students about module changes in accordance with the University's policy on the Approval of Modifications to Existing Taught Programmes of Study.