Physicists working up from atoms to Schrodinger's cat

January 28, 2009 by Lisa Zyga weblog

( -- Schrodinger's cat, a macroscopic object that is both alive and dead at the same time, illustrates the strangeness of quantum mechanics. While such quantum properties have been widely observed for electrons and molecules, recent experiments have shown that larger objects may also demonstrate quantum effects. Just how large, though, is still an open question.

In the emerging field of cavity optomechanics, physicists may have the opportunity to investigate the boundary between quantum and classical systems. Optomechanical systems are mechanical systems that can be manipulated by light - for example, a thin membrane being vibrated by light in an optical cavity. Two recent studies have proposed that, with current technology, it should be possible to cool down two of these millimeter-scale membranes in such a way that they act like a single molecule. No matter how far apart they are, the membranes could be interrelated through quantum entanglement, so that measuring one membrane instantly affects the other.

In a study published in Physical Review A last October, physicists Mishkat Bhattacharya and Pierre Meystre from the University of Arizona in Tucson took the first steps toward showing how a pair of vibrating membranes can form a molecule-like state. By interacting with photons from a laser, the membranes become coupled together. According to the scientists' calculations, this results in a state with two different modes with different resonant frequencies: in one mode, the membranes move together, while in the other mode, the membranes move opposite to each other. By shining a particular laser frequency on the membranes, it should be possible to cool down each mode's vibrations separately. Since these vibrational states are analogous to the excitations of a single molecule, the experiment demonstrates how the two membranes act as a single system.

In a second study published in Physical Review Letters last November, Michael Hartmann and Martin Plenio of Imperial College London proposed a similar experiment, with the additional step of entangling the two membranes. The researchers calculated that, by using certain laser frequencies to cool the modes, the interactions between them could entangle the membranes for as long as the lasers remain on. Two weak lasers could then verify the entanglement without destroying it.

Experimentally demonstrating this membrane entanglement will require precise and challenging methods, but the results could enable physicists to investigate the transition from the quantum to classical world.

More information:

M. Bhattacharya and P. Meystre. "Multiple membrane cavity optomechanics." Physical Review A 78, 041801(R) (2008).

M. J. Hartmann and M. B. Plenio. "Steady State Entanglement in the Mechanical Vibrations of Two Dielectric Membranes." Physical Review Letters 101, 200503 (2008).

via: CERN Courier and Physical Review Focus

Explore further: Gold Quantum Dots: Fluorescing "Artificial Atoms" Could Have Applications in Biological Labeling, Nanoscale Optoelectron

Related Stories

Quantum Criticality in life's proteins (Update)

April 15, 2015

(—Stuart Kauffman, from the University of Calgary, and several of his colleagues have recently published a paper on the Arxiv server titled 'Quantum Criticality at the Origins of Life'. The idea of a quantum criticality, ...

Tiny sensors put the squeeze on light

October 24, 2013

Microelectromechanical systems, known as MEMS, are ubiquitous in modern military systems such as gyroscopes for navigation, tiny microphones for lightweight radios, and medical biosensors for assessing the wounded. Such applications ...

Researchers Assess the Evolution of Quantum Dot Imaging

February 3, 2005

The evolution over the last two decades of the nanocrystals known as quantum dots has seen the growth of this revolutionary new tool from electronic materials science to far-reaching biological applications that will allow ...

New knowledge about the remarkable properties of black holes

December 11, 2012

Black holes are surrounded by many mysteries, but now researchers from the Niels Bohr Institute, among others, have come up with new groundbreaking theories that can explain several of their properties. The research shows ...

Recommended for you

Exploring the physics of a chocolate fountain

November 24, 2015

A mathematics student has worked out the secrets of how chocolate behaves in a chocolate fountain, answering the age-old question of why the falling 'curtain' of chocolate surprisingly pulls inwards rather than going straight ...

Biomedical imaging at one-thousandth the cost

November 23, 2015

MIT researchers have developed a biomedical imaging system that could ultimately replace a $100,000 piece of a lab equipment with components that cost just hundreds of dollars.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jan 28, 2009
I want to quantumly entagle myself with a puppet. Best ventriloquist act ever!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.