Cavity optomechanics deals with interaction of light with mechanical motion. In general, mesoscopic or macroscopic mechanical oscillator(in nano scale) are used to explore boundaries between Quantum domain and classical domain.
Can a mechanical oscillator of mass 1 gm be used in cavity optomechancs(like a memebrane) to explore the Quantum effects?.
Hi, Anil !
I don't deal with opto-mechanics, but let me tell you some general things. In order to do a measurement on a certain property/variable of a quantum particle, you have first to create an entanglement between the values of that variable and something that we can measure directly. For instance, you know that in order to measure the spin-projection of a particle along a certain direction in space, we entangle the spin projection with the linear momentum of the particle, s.t. in the Stern-Gerlach apparatus the waves carrying different values of the spin projection fly in different directions getting spacely-separated.
I don't know the experiment that you have in mind - you have to describe it, but let me assume that you would want the 1g mass to move. Let's then calculate with which velocity this mass should move such that the wavelength be as big as 1 nanometer, i.e. 10 times the radius of the Hydrogen atom. As we know,
λ = h/(mv)
Here h is Planck's constant, h = 2πħ ≈ 6.28 x 10-27erg sec. , m = 1g, λ = 10-7cm as we required, s.t. there results v = h/(mλ) = 6.28 x 10-20cm/sec.
How can you record such terribly small velocities? As please note that we required a less than nanometer wavelength. If we expect a bigger wavelength, the velocity would be even smaller.
Therefore, 1g. is too big a mass. Even if you try with a nano-gram, 10-9g, you get a velocity of 6.28 x 10-11cm/sec.
So, in my modest opinion you need something much lighter. For achieving a velocity of 1cm/s you need a mass of 10-21g. Take in consideration that an atom of Carbon weighs 2 x 10-23g. Then, what you need as the mass, is, maybe, a living molecule with hundreds of C atoms.
Best regards,
Sofia
Hi, Anil!
As I mentioned that a macromolecule might be a solution instead of the 1g mass, let me mention the experiments of the Zeilinger group with interference of such molecules. I attach some references, but you can see many experiments in the arXiv:quant-ph. Maybe you'd find some inspiration there.
The quantum effect is very weak in the macroscopic of view. The calculations of Sofia upstairs can indeed give you estimation that 1 gm is a very large mass for a detection of its quantum behavior. So you can do it by using one layer of graphite membrane to explore the Quantum effects with opto-mechanics.