Quantum systems engineering

Abstract:

A master equation for the reduced density operator of the Bose-Einstein condensate was formulated using the quantum kinetic theory. The steady state of the system is calculated and the effect of the one-, two-, and three-particle losses on the condensate is investigated. The effect of trap losses on the particle statistics is also studied. The condensate particles are coherently pumped into an untrapped internal energy level and fall down in gravity. The relation between the statistics of the trapped condensate particles and the statistics of the particles arriving at an atom detector positioned below the condensate are derived.

Abstract:

Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions.