Abstract:

One of the most basic but intriguing properties of quantum systems is their ability to ‘tunnel’ between classically disconnected regions of phase space. That is, processes which are classically not just slow, but impossible, become allowed. In this talk I will describe a new, elementary approach which combines the semiclassical approximation with post-selection and weak measurement to obtain a real-time description within which sharp answers can be given to questions like: ‘how did the particle tunnel?’ and ‘where was it while it was tunneling?’ Potential applications span a vast range, from laboratory tests using quantum dots to quantum chemistry, understanding the Hawking process of black hole evaporation and even the legitimacy of the “inflationary multiverse” picture. Furthermore, recent LHC data (with the assumption of minimality) implies our universe may quantum tunnel in the future, with striking consequences.