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NEWS

Dr Maarten Hoogerland

University of Auckland

Monday, December 2nd, 2013 at 11:00:00 AM

Conference room Querzoli - LENS - via Nello Carrara 1 - Sesto Fiorentino (Florence)

Published on-line at 05:45:58 PM on Wednesday, November 27th, 2013

A Phase-Engineered Quantum Ratchet showing directional motion in absence of a directional force

A Brownian ratchet, which gives directional motion in absence of a directional force, is familiar from Feynman's lectures on physics, where he shows that it wil

A Brownian ratchet, which gives directional motion in absence of a directional force, is familiar from Feynman's lectures on physics, where he shows that it will not work. We observe quantum ratchet behavior in the delta-kicked rotor system, which is a classically chaotic system which we study in the quantum domain.  We show clear directed momentum current in the absence of a directional force. We use a Bose-Einstein Condensate as the source of ultra-cold atoms, and employ asymmetric phase modulation in the kicks, whilst the narrow momentum distribution of the atoms allows us to address individual island structures in phase space. We characterize and connect our experiments to ε–classical theory

For further informations, please contact Prof. Giovanni Modugno.