The Adiabatic Probing of Macroscopic Quantum Objects

Timothy P. Spiller, Terrence D. Clark, Robert J. Prance +1 more

Aslani, Mahdi, Abdi, Mehdi

Since the establishment of the quantum mechanics, researchers in physics have been studying superposition states and especially proposing setups for generating macroscopic objects in a quantum superposition state. Such states are important and of interest both from a foundational perspective and for their applications in the emerging quantum technologies. Here, we propose a circuit quantum electrodynamical setup and an adiabatic scheme for preparing a macroscopic and massive object in a quantum superposition state. The scheme is based on establishing a spatial double-well potential for a macroscopic object and preparing it in the ground state of the potential via an adiabatic transition. The resulting state is a spatial superposition state where the object assumes a superposition of bulked to two opposite directions, e.g. right and left. By numerical solving of the quantum optical master equation and including the environmental effects, we show that the target cat state is achievable with a high fidelity provided the process satisfies the adiabaticity conditions.

Haixing Miao

Sougato Bose, Kurt A. Jacobs, P. L. Knight

We propose a quantum optical version of Schr\"odinger's famous gedanken experiment in which the state of a microscopic system (a cavity field) becomes entangled with and disentangled from the state of a massive object (a movable mirror). Despite the fact that a mixture of Schr\"odinger cat states is produced during the evolution (due to the fact that the macroscopic mirror starts off in a thermal state), this setup allows us to systematically probe the rules by which a superposition of spatially separated states of a macroscopic object decoheres. The parameter regime required to test environment-induced decoherence models is found to be close to those currently realizable, while that required to detect gravitationally induced collapse is well beyond current technology.

Michel Devoret, John M. Martinis, Esteve, Daniel

Sougato Bose, Kurt A. Jacobs, P. L. Knight

Summary form only given. We describe how a quantum optical system can be used to probe the rules according to which the decay of a superposition of spatially separated states of a macroscopic object takes place. We consider a system composed of an electromagnetic field mode inside a cavity exerting pressure on a movable harmonically oscillating mirror of the cavity. Both the movable mirror and the cavity field are treated as quantum harmonic oscillators with the number operator of the field being coupled to the position operator of the mirror.