2011-07-19Schrodinger chameleon |
The well known though experiment, named Schrodinger cat, illustrates the paradox of quantum mechanics, which requires that any superposition of two allowed states is also a possible state of a system. Thus one of the fathers of the Quantum Mechanics, Erwin Schrodinger, proposed that a cat could be, theoretically speaking, prepared in a state of superposition of being dead and alive at the same time. Modern experimental science is unable to create such strange cats.
Yet, experimentalists have succeeded in creating superpositions of photons with different colors. In the classical world one thinks that a photon is an electromagnetic wave that has certain frequency. In the quantum world a photon can have a few frequencies at once, thanks to the Schrodinger's principle of quantum superposition. Since the frequency of the photon defines its color, the superposition photon has more than one distinct color at once. Thus it can be termed ''Schrodinger chameleon''.
NIST research group led by Aumentado has created an "optics table on a chip", which is a thin-film two-dimensional superconducting circuit on a sapphire substrate, less than one inch in size. The created superconducting device is an analogue of the Fabry-Perot resonator, but it works with microwave photons. The superposition photon with a superposition frequency or color is prepared by so called "artificial atom". The artificial atom is also a superconducting structure, which is similar to a SQUID or a superconducting qubit. The resonance frequency of the Fabry-Perot resonator depends on the state of the qubit. Since the SQUID qubit can be in a superposition of two distinct sates (this is the main property of a qubit), the resonator itself can be prepared in a superposition of two resonance frequencies. Thus it stabilizes superposition-photons. The results are published in Nature Physics (E. Zakka-Bajjani, F. Nguyen, M. Lee, L.R. Vale, R.W. Simmonds and J. Aumentado. Quantum superposition of a single microwave photon in two different 'colour' states. Nature Physics. Posted online July 3, 2011.)
Schrodinger chameleon
