COLLOQUIUM

 

16:00 (CET) March 12,  Prof. Dr. Brian R. D'Urso  (Montana State University)

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Towards Precision Pulsed Levitated Optomechanics in a Magneto-Gravitational Trap

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 Magneto-gravitational traps use the repulsion of diamagnetic materials by magnetic fields combined with the Earth's gravity to create a weak trap for micrometer-scale diamagnetic particles. A single particle levitated in this trap oscillates harmonically in three dimensions and its position can be measured optically. We have previously demonstrated feedback cooling of a trapped particle using radiation pressure from a second light source, but the low frequencies of oscillation appear to make quantum behavior unreachable, at least on long time scales. We report on progress towards observing the quantum limit of the motion by optical measurements of the particle position on time scales short compared to the oscillation period of the motion, making the behavior approach that of a free particle. We also show that classical pulsed measurements on larger trapped particles can reach remarkably high precision and demonstrate the performance by using it to measure vibrations of the system. Finally, we examine the possibility of coupling the mechanical motion with spins associated with defect states in trapped silicon carbide particles for generating macroscopic superposition states.