# LIGHT AND MATTER - 2021/2

Module code: PHY3043

## Module Overview

The module is about quantum optics, which is the way that quanta of light interact with quantum objects. In Schrödinger’s famous cat paradox the animal was both alive and dead at the same time, but the thought experiment itself was pretty boring – just set up the cat, in a box, with some poison, a detector, and some radio-active substance, and let nature take its course. If you look in the box and repeat with many cats, sometimes they’re alive and sometimes dead, with a simple probability distribution determined by how long you wait. Quantum optics adds control – want the cat a bit more alive than dead? Want it completely dead? Want it to spring back to rude health? Just dial in the appropriate laser pulses and your ghostly quantum object (probably not a cat) will obey your command, just so long as you aren’t tempted to look at it. What useful things can you do with these ideas? Magnetic Resonance Imaging is one of the very few commercially available technologies that uses quantum superpositions, other than some fairly simple, but uncrackable, quantum encryption key transmission systems. But the future looks really bright, and possibly most excitingly, Quantum Computers will also take advantage of entanglement. In this effect, you can measure one bit of the entangled system and instantly find stuff out about others, no matter how far away they are. Even more amazing, you can fiddle around with some of the bits of the system and that has an instant effect on the others, even though they could be miles away and you don't touch them. Some detractors point out that there are not many quantum programs that have been shown to be better than classical computers, which are already doing pretty well thank you very much, but of course one of the problems is that so few people understand quantum computing enough to write them. After all, the hardware doesn't really exist yet! It’s just a symptom of an exploding subject in its infancy, and this module will even give you the tools to take part.

### Module provider

Mathematics & Physics

### Module Leader

MURDIN Benedict (Physics)

### Number of Credits: 15

### ECTS Credits: 7.5

### Framework: FHEQ Level 6

### Module cap (Maximum number of students): N/A

## Overall student workload

Independent Learning Hours: 67

Seminar Hours: 6

Tutorial Hours: 11

Guided Learning: 55

Captured Content: 11

## Module Availability

Semester 1

## Prerequisites / Co-requisites

The module will assume prior knowledge equivalent to the following modules. If you have not taken these modules you should consult the module descriptors Level HE1 (FHEQ Level 4) Mathematical And Computational Physics PHY1038; Atoms And Quanta PHY1040 Level HE2 (FHEQ Level 5) From Atoms to Lasers PHY2062; Energy and Entropy PHY2063; Electromagnetic Waves PHY2065; Electromagnetism, Scalar and Vector Fields PHY2064; Quantum Physics PHY2069

## Module content

Each sub-unit is 1 week: 2 hours lecture + 1 hour seminar/tutorial.

**1. Atoms **

The gas of classical oscillators and Rayleigh scattering. The Bohr model and its failures. Formalism of wave mechanics, Dirac notation. Spherical harmonics and the hydrogenic atom [without proof].

**2. Magnetic Circular Dichroism**

Static field perturbations: the hydrogenic atom in a magnetic field. Circular polarization and selection rules.

**3 Quantum matter and classical light waves**

The two-level atom: the Time-Dependent Schrödinger equation and Rabi oscillations.

**4 Echoes **

Photon echoes, pulsed Nuclear Magnetic Resonance (NMR)/Electron Spin Resonance (ESR) and spin echoes. Application of NMR to Magnetic Resonance Imaging (MRI).

**5 Advanced quantum optics **

Dressed states, electromagnetically induced transparency and slow light. Fermi’s Golden Rule.

**6. Photon Statistics and squeezed light**

Classical intensity interferometers and astronomical applications: Hanbury Brown–Twiss experiments. Coherent light and Poissonian photon statistics, sub-Poissonian photon statistics, the quantum HBT experiment, single-photon sources, squeezed states.

**7. Quantum matter and quantum light**

Introduction to the second quantization, photon number states, raising and lowering operators, the Jaynes Cummings Model.

**8. Cold atoms and ions in cavities and traps**

Laser cooling, and Bose-Einstein condensation. Optical cavities, atom-cavity coupling, weak and strong coupling. Atomic clocks, the atom laser.

**9. Quantum cryptography**

Quantum Cryptography and practical implementations.

**10. Quantum computing and entangled states**

quantum bits, quantum logic and states, and quantum computer algorithms: the quantum Fourier Transform. Entangled states, quantum teleportation.

## Assessment pattern

Assessment type | Unit of assessment | Weighting |
---|---|---|

Online Scheduled Summative Class Test | WEEKLY QUESTIONS ON SURREYLEARN | 10 |

Coursework | COMPUTING COURSEWORK | 30 |

Examination Online | ONLINE (OPEN BOOK) EXAM | 60 |

## Alternative Assessment

N/A

## Assessment Strategy

The __assessment strategy__ is designed to provide students with the opportunity to demonstrate

- analytical ability by solution of unseen problems in both coursework and exam
- subject knowledge by recall of both “textbook” theory and important research articles in the exam
- practical skill by completion of a laboratory quantum optics experiment (coursework option E)
- practical skill by writing a computer program for matrix mechanics/quantum optics calculation (coursework option C) practical skill by solving a theoretical problem in matrix mechanics/quantum optics (coursework option T)
- ability to generalize textbook theory by openended research component in the coursework

Thus, the

__summative assessment__for this module consists of:

- a 1.5 hour exam, with a choice of two questions from three. The total exam mark is weighted at 70%
- coursework, which will take about 40 hours of effort with a choice of one option from three: a computing option; a theory option; and an experimental option (with some limitations on the equipment availability for the latter). The submission will be in three parts spread out through the semester. The total coursework mark is weighted at 30%

__Formative assessment and feedback__

- Students will receive verbal feedback on progress with problems in tutorials and model solutions to the tutorial questions, and can participate in on-line discussion boards. There is formative feedback on each of the first two coursework submissions directly relevant to each subsequent part.

## Module aims

- This module aims to: provide an understanding of the fundamentals, links and recent developments in atomic physics and quantum optics.

## Learning outcomes

Attributes Developed | ||

1 | Compare and contrast the behaviour of classical oscillators in classical waves with that of quantum oscillators interacting with photons | KC |

2 | Apply the time-dependent Schrödinger equation to a two level atom to produce superpositions and their evolution | KC |

3 | Explain the causes of quantum optical phenomena such as photon echoes | K |

4 | Relate quantum optical principles to real-life applications using photon echoes such as magnetic resonance imaging | KC |

5 | Theorize or generalize in unseen situations where quantum optics concepts apply | C |

Attributes Developed

**C** - Cognitive/analytical

**K** - Subject knowledge

**T** - Transferable skills

**P** - Professional/Practical skills

## Methods of Teaching / Learning

The __learning and teaching__ strategy is designed to provide:

- a comprehensive theoretical treatment for the subject knowledge
- practice in problem solving for the cognitive skills

The

__learning and teaching__methods include:

- “chalk and talk” lectures backed up with guided study to stimulate uptake of subject knowledge (2 hour per week x 10)
- seminar-type discussion forums of the key concepts including “classic” research articles and reviews describing applications of theory (0.5 hour per week x 10)
- tutorial demonstration of solutions to key problems after students have attempted them for formative feedback (0.5 hour per week x 10)
- peer learning and teaching with structured Surrey-Learn hosted discussion boards focussed on the above (constant)

Indicated Lecture Hours (which may also include seminars, tutorials, workshops and other contact time) are approximate and may include in-class tests where one or more of these are an assessment on the module. In-class tests are scheduled/organised separately to taught content and will be published on to student personal timetables, where they apply to taken modules, as soon as they are finalised by central administration. This will usually be after the initial publication of the teaching timetable for the relevant semester.

## Reading list

https://readinglists.surrey.ac.uk

Upon accessing the reading list, please search for the module using the module code: **PHY3043**

## Programmes this module appears in

Programme | Semester | Classification | Qualifying conditions |
---|---|---|---|

Physics with Astronomy BSc (Hons) | 1 | Optional | A weighted aggregate mark of 40% is required to pass the module |

Physics with Quantum Technologies BSc (Hons) | 1 | Compulsory | A weighted aggregate mark of 40% is required to pass the module |

Physics BSc (Hons) | 1 | Optional | A weighted aggregate mark of 40% is required to pass the module |

Physics with Nuclear Astrophysics MPhys | 1 | Optional | A weighted aggregate mark of 40% is required to pass the module |

Physics with Astronomy MPhys | 1 | Optional | A weighted aggregate mark of 40% is required to pass the module |

Physics MSc | 1 | Optional | A weighted aggregate mark of 40% is required to pass the module |

Physics with Nuclear Astrophysics BSc (Hons) | 1 | Optional | A weighted aggregate mark of 40% is required to pass the module |

Physics with Quantum Technologies MPhys | 1 | Compulsory | A weighted aggregate mark of 40% is required to pass the module |

Physics MPhys | 1 | Optional | A weighted aggregate mark of 40% is required to pass the module |

Please note that the information detailed within this record is accurate at the time of publishing and may be subject to change. This record contains information for the most up to date version of the programme / module for the 2021/2 academic year.