Theoretical Physics/Maths Seminar: Paul Fendley (Oxford)

Date: 13/11/2017

Time: 16:00-17:00

Location: EC Stoner 9.90

Preserving Quantum Coherence

Considerable effort is being made to develop new methods of preserving quantum coherence, i.e. enabling quantum effects to be maintained for times long enough to exploit them for computations. I will survey three such methods, all involving deep mathematics. One is to find systems where topological invariants such as Chern number protect certain quantum properties. Another is to exploit integrability, where the presence of many conserved quantities strongly constrains the dynamics. Still another is prethermalisation, where a recent theorem shows there is always an almost-conserved charge in systems where the dominant term in the Hamiltonian has integer eigenvalues. I will explain a specific example that combines aspects of all three: quantum spin chains with an edge strong zero mode.