Bradley Slezak Received His Ph.D. Degree 

Bradley Slezak was a graduate student under the supervision of Wolfgang J. Choyke and Brian D'Russo.

This spring he has successfully passed his Ph.D. defense. On Thursday, April 26, 2018 he attended the commencement ceremony at the John M. and Gertrude E. Petersen Events Center to receive his degree.

His research involved measuring the decoherence rate of non-classical states of the trapped particle.

Along with Dr. Brian D'Urso, they set out to combine a mechanical system in which classical mechanics breaks down and quantum mechanics must be used with a seemingly unlikely application: measurements of the strength and effects of gravity. 

Our system consists of a silica particle levitated in ultra-high vacuum.  This diamagnetic particle is trapped in a magnetic field gradient created by permanent magnets and ferromagnetic pole pieces. 

The motion of the particle is measured by scattering light off of the particle, resulting in a non-negligible radiation force.  With feedback based on the detected velocity, the mechanical motion cab be cooled by several orders of magnitude, ideally reaching the quantum ground state. 

By measuring the decoherence rate of non-classical states of the trapped particle, we may be able to place limits on theories of gravitational decoherence. 

Furthermore, the extreme sensitivity of our system to external forces makes it a promising approach to a new measurement of the Newtonian gravitational constant.

Congratulations Dr. Bradley Slezak !