researchers at the university of arkansas (fayetteville) have defined a new cooling limit for optomechanical cooling, a process that theoretically could cool an object to its pure quantum state where all thermal energy is removed, which has applications in quantum computing, according to an article from the school.

researchers have set a new quantum cooling limit for optomechanical cooling.
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optomechanical cooling involves applying a tuned light field to an object (a mechanical oscillator in this particular case) to cool that object. pressure from photons converts the energy stored in the object as thermal phonons into photons. because of noise perturbations in the environment, true quantum state cannot be achieved, but the arkansas researchers have defined a new cooling limit.

the new research demonstrates that the speed in which the cooling takes place defines the state that will be achieved, according to one of the researchers, and a new dynamic picture of the optomechanical cooling process shows how the heating and cooling of the object proceeds.

this new picture of the process allows researchers to determine the precise conditions necessary for achieving best cooling of the system.

the research was recently published in physical review letters. the abstract stated:

“one of the most fundamental problems in optomechanical cooling is how small the thermal phonon number of a mechanical oscillator can be achieved under the radiation pressure of a proper cavity field. different from previous theoretical predictions, which were based on an optomechanical system’s time-independent steady states, we treat such cooling as a dynamical process of driving the mechanical oscillator from its initial thermal state, due to its thermal equilibrium with the environment, to a stabilized quantum state of higher purity.

“we find that the stabilized thermal phonon number left in the end actually depends on how fast the cooling process could be. the cooling speed is decided by an effective optomechanical coupling intensity, which constitutes an essential parameter for cooling, in addition to the sideband resolution parameter that has been considered in other theoretical studies.

“the limiting thermal phonon number that any cooling process cannot surpass exhibits a discontinuous jump across a certain value of the parameter.”