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Friday, February 26, 2016
4:00 PM - 5:00 PM
East Bridge 114

IQIM Postdoctoral and Graduate Student Seminar

Casimir Effect, Theta Vacuum and Topological Order in QED
Charles Cao, Graduate Student, Physics, Caltech,

Abstract: We analyze the case where one imposes non-trivial spatal topology for a simple abelian gaug theory. As usual,the large gauge transformatons present in the system allow one to discuss theta vacuum and magneto-electric effect via the theta term. However, even for zero theta parameter, the tunneling transitions between different topologically inequivalent pre-vacua give rise to an additional contribution to vacuum energy that can be measured in the context of Casimir effect. Furthermore, photon production and non-trivial electric and magnetic responses can be induced by applying a global external field which behaves similar to an effective theta parameter. The theory in the far IR can be described by a TQFT and a phase transition occurs at effective theta = pi where the quantum vacuum has degeneracy two. Possible experimental implementations will also be discussed.


 

 

For more information, please contact Marcia Brown by phone at 626-395-4013 or by email at marciab@caltech.edu.