ITAMP/HQOC Joint Quantum Sciences Seminar
Wednesday, September 26, 2018
4:00 PM, Jefferson 250
Prof. Margaret Reid, Swinburne University of Technology
“Mesosopic Einstein-Podolsky-Rosen states of massive systems”
The demonstration of long-lived entanglement between two separated massive systems opens
up the possibility of new tests of quantum mechanics and decoherence theories. For
example, the intriguing idea of spatially dependent decoherence was put forward by Furry
[1] in response to Einstein-Podolsky-Rosen’s (EPR) paradox paper [2], which highlighted
the inconsistency of quantum mechanics with the classical premise of local realism.
Furry’s hypothesis is not a part of conventional quantum mechanics. It could occur in a
modified quantum mechanics. In the EPR paradox, a measurement made by an observer at one
location can seemingly instantaneously affect the quantum state at another. States that
demonstrate the correlations of an EPR paradox were thus called “steerable” by
Schrodinger. Here, we will present evidence for EPR steerable entangled states of 40,000
atoms generated in a Bose-Einstein condensate [3]. The structure of the correlations can
be further analysed, to deduce miniature cat-type paradoxes with atoms. In order to
investigate EPR steerable states with spatial separations, we present a protocol for
creating, storing and retrieving EPR steerable states of an opto-mechanical oscillator
[4]. This leads us to consider
the possibility of generating mechanical Schrodinger cat-states, and to test macroscopic
realism for massive systems using Leggett–Garg and Bell inequalities in time.
Prof. Peter D Drummond, Swinburne University of Technology
“Simulations of many-body systems: Furry and Coleman revisited”
Wendell Furry [1] and Sydney Coleman [5] were two of Harvard's most original quantum
theorists. What can modern technology contribute to their work? Experimentally tested
simulations of optomechanics[4] and atom interferometers [3], with thermal noise and
losses, will be used to analyse proposals for testing Furry's nonlocal decoherence,
and Coleman's QFT tunnelling to the true vacuum. Both entanglement decoherence and
massive Schrodinger cats are testable [4] through an optomechanical memory, simulated
using the positive-P representation. Coleman's vacuum tunneling idea will be applied
to construct a proposal for a laboratory model of the quantum fluctuations in the
'Big Bang', using a coupled BEC experiment simulated with a Wigner
representation [6].
[1] W. H. Furry, Phys. Rev. 49, 393 (1936). [2] A. Einstein, B. Podolsky, and N. Rosen,
Phys. Rev. 47, 777 (1935). [3] M. Egorov et. al, Phys. Rev.
A 84, 021605 (2011). [4] S. Kiesewetter, R. Y. Teh, P. Drummond and M. Reid, Phys. Rev.
Lett. 119, 023601 (2017). [5] S. Coleman, Phys. Rev. D 15, 2929
(1977). [6] O. Fialko et. al., J. Phys. B 50 024003 (2017).
Refreshments provided at 4:00 pm.
Samantha Dakoulas
Faculty Assistant to Professors Lukin & Greiner & their groups
Department of Physics
17 Oxford St., Lyman 324A
Cambridge, MA 02138
P. (617) 496-2544
Show replies by date