Applications of Quantum Optics and Nano-scale device fabrication to Quantum Mechanics and Quantum Information Processing

This talk will cover a few experiments and theoretical problems that I have been working on in recent times and would like to work on in my future appointment.  

The first section will deal with an experiment that we completed recently and the results were published in Science [1].  

As one of the postulates of quantum mechanics, Born's rule tells us how to get probabilities for experimental outcomes from the complex wave function of the system. It's quadratic nature entails that interference occurs in pairs of paths. An experiment was done in our laboratory that sets out to test the correctness of Born's rule by testing for the presence or absence of genuine three-path interference. This is done using single photons and a triple slit aperture. 

Although the Born rule has been indirectly verified to high accuracy in other experiments, the consequences of a detection of even a small three-way interference in the quantum mechanical null prediction are tremendous. If a non-zero result were to be obtained, it would mean that quantum mechanics is only approximate, in the same way that the double slit experiment proves that classical physics is only an approximation to the true law of nature. This would give us an important hint on how to generalize quantum mechanics and open a new window to the world. In this talk, I will show results that bound the possible violation of Born’s rule and multi-path interference in quantum mechanics and will point out ways to obtain a tighter experimental bound. I will then describe other possible future implementations of the experiment as well as a promising application to qutrit based quantum computing. 

My PhD in the University of Cambridge, UK dealt with applications of experimental superconductivity and nano scale device fabrication, characterization and optimization [2,3,4,5]. In my future appointment, I would like to devote a portion of my research direction towards combining my interests in quantum optics and experimental superconductivity and nanotechnology towards a finite research goal. I will spend a part of this talk discussing and describing such potential experiments as well as some of my recent theoretical work on decoherence  which has important consequences for Josephson junction based quantum computing. 

1. U.Sinha, C.Couteau, T.Jennewein, R.Laflamme and G.Weihs, Science 329 418-421, 2010. 
2. U.Sinha, A.Sinha and F.K.Wilhelm, Superconductor Science and Technology 22, (2009), 055002. 
3. U.Sinha, A. Sinha and E.J. Tarte, Superconductor Science and Technology 21, (2008), 085021. 
4. U.Sinha, G.Burnell, M.G.Blamire and E.J.Tarte, Superconductor Science and Technology 19, 427- 
    432, 2006. 
5. U.Sinha, P.F.McBrien, S.H.Menemma, D.Zhang, D.S.Pinker, G.Burnell, Z.H.Barber and E.J.Tarte, 
    Ferroelectrics 329, 1029-1034, 2005