seminar: Dynamics of spin chains in periodically pulsed magnetic fields
speaker: Tom Boness (University College London)abstract: There is currently much interest in manipulating the dynamics of low-level excitations in spin chains for purposes such as state transfer and the generation and distribution of entanglement. We consider the dynamics of a single spin-flip on a ferromagnetic Heisenberg chain subjected to a periodic pulsing from an external, parabolic, magnetic field. We show that the spin excitation in this case behaves analogously to a Quantum Kicked Rotor (QKR), a key model of quantum chaos PRL, 96, 187201 (2006). Using this connection, we can investigate the influence of chaos on the evolution of the excitation, which displays some novel behavior. Typically, the excitation will become exponentially localized about its starting point, but under certain parameters it is converted to an entangled pair of counter-propagating coherent excitations. We show that similar chains can also be used to simulate variations of the QKR,arxiv:quant-ph/0612074 and how these provide alternative ways of manipulating the spin excitations.
timetable:
Tue 27 Mar, 11:20 - 11:50, Aula Dini
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