PHYM425 Quantum Devices

2007-2008

Aims

Our ability to transmit and process information has reached the level where it can exploit the properties of single quanta. Although such systems are not yet in commercial use, practical demonstrations have already been made - for example of quantum cryptography. Devices based on single photons and single electrons are set to provide a new era in information processing. In addition to their potential applications, these phenomena continue to provide new ways to probe our understanding of the world and allow us to explore new physics.

This module shows how the fundamental physics learned in previous core modules on quantum mechanics, solid-state and statistical physics, can be used as a basis to describe and explain these new devices. As well as demonstrating the application of physics to technology, the module also provides helpful grounding for students interested in careers in the electronics, optoelectronics and photonics industries.

Intended Learning Outcomes

Students should be able to:

Module Specific Skills

• describe the physical principles and operation of a range of quantum devices, and the methods used to fabricate and characterise such devices;
• demonstrate an understanding of quantum based devices by being able to solve a range of problems relating to theml
• critically appraise the advantages and disadvantages associated of quantum devices in a range of applications;

Discipline Specific Skills

• discover and evaluate technical information from a variety of sources;
• solve problems which require discovery of information;

Personal and Key Skills

• communicate technical information in a succinct and precise manner.

Learning and Teaching Methods

Directed self-study; use of online resources; student presentations and seminars.

Assignments

One practice written report (2500 words); presentation to group; two written reports (2500 words). The Assessment Criteria are published in the School Handbook.

Assessment

Oral Presentation (20%), two written reports (40% each).

Note: Referred assessment, in the form of essays written under examination conditions, is available for this module. See also the School of Physics Examination Conventions.

Syllabus Plan and Content

Because of the rapid change in this area, the applications will be drawn from current research and so those given below are for guidance only.

1. Photon detectors
   Semiconductor based photo detectors; Charge-coupled devices; Photomultipliers.
2. Microcavities
3. Quantum Dots
4. Quantum Dot lasers
5. The need for devices based on exploiting quantum mechanics
   Faster processing rates, greater bandwidth in transmission systems; secure communication; the light-speed limit; the quantum limits. Moore's "Law".
6. Quantum electron devices
   Size matters; low dimensions; Coulomb blockade devices; resonant tunnelling devices; quantum oscillators; new approaches: spin valves, organics, self organising systems.
7. Devices based on quantum interference
   Josephson junctions, the squid; flux logic; mesoscopic devices.
8. Quantum cryptography
   Quantum entanglement; secure communication; teleportation.
9. Quantum computing
   Coherence and incoherence; quantum algorithms; implementation: qubits, magnetic resonance, single electron logic.

Core Text

Supplementary Text(s)

Formative Mechanisms

The practice report is assessed by the instructor and there is a detailed follow-up discussion. Presentations receive specific feedback from the module instructor and are peer-assessed by the student group.

Evaluation Mechanisms

The module will be evaluated using information gathered via the student representation mechanisms, the staff peer appraisal scheme, and measures of student attainment based on summative assessment.