Quantum Mechanics Tackles Mechanics
The controlled generation and verification of quantum entanglement of a mesoscopic mechanical device (a mechanical oscillator) with an electromagnetic microwave field is reported.
Abstract
A micromechanical oscillator can only be described with quantum mechanics after it is entangled with microwave fields. [Also see Report by Palomaki et al.] Quantum theory describes the physical cosmos at atomic and smaller scales, but can we apply quantum mechanics to large, distributed mechanical structures? Several recent experiments have shown that we can observe quantum dynamics of nano- and micromechanical oscillators. On page 710 of this issue, Palomaki et al. (1) report the controlled generation and verification of quantum entanglement of a mesoscopic mechanical device (a mechanical oscillator) with an electromagnetic microwave field. Entanglement is considered to be the distinguishing feature that separates quantum from classical physics. Only the properties of the entire system have precise values, and the mechanical resonator and the microwave field must be described by one compound quantum-mechanical wave function. No such wave functions can be assigned to either of the subsystems separately.