How would you look for something that can be in two 'places' at once? The answer, according to Oxford University research into a quantum phenomenon called superposition, seems to be to ask where it isn't rather than where it is. Read more
World-famous mathematician and physicist Sir Roger Penrose is Lorentz Professor 2011 at Leiden University. But his links with Leiden go back much further than this. Together with Leiden experimental physicists Dirk Bouwmeester and Tjerk Oosterkamp he is seeking the limits of quantum mechanics. Penrose wanted to look for the limits of quantum mechanics. It is something he has been interested in for many years, he explains. In theory, quantum mechanics should always apply, but the fact is that this is not what we perceive. Take one of the phenomena in the quantum world, known as superposition, where particles can be found in several places at the same time. Penrose: 'That sounds strange and it is something we don't see in everyday life. Apparently there is a limit to this superposition.' In his view, the cause for this can be found in the theory of gravity.
Huge molecules can show the wave-particle duality of quantum theory
Researchers in Austria have made what they call the "fattest Schrödinger cats realized to date". They have demonstrated quantum superposition - in which an object exists in two or more states simultaneously - for molecules composed of up to 430 atoms each, several times larger than molecules used in previous such experiments. Read more
Title: Towards Quantum Superposition of Living Organisms Authors: Oriol Romero-Isart, Mathieu L. Juan, Romain Quidant, J. Ignacio Cirac
The most striking feature of quantum mechanics is the existence of superposition states, where an object appears to be in different situations at the same time. Up to now, the existence of such states has been tested with small objects, like atoms, ions, electrons and photons, and even with molecules. Recently, it has been even possible to create superpositions of collections of photons, atoms, or Cooper pairs. Current progress in optomechanical systems may soon allow us to create superpositions of even larger objects, like micro-sized mirrors or cantilevers, and thus to test quantum mechanical phenomena at larger scales. Here we propose a method to cool down and create quantum superpositions of the motion of sub-wavelength, arbitrarily shaped dielectric objects trapped inside a high--finesse cavity at a very low pressure. Our method is ideally suited for the smallest living organisms, such as viruses, which survive under low vacuum pressures, and optically behave as dielectric objects. This opens up the possibility of testing the quantum nature of living organisms by creating quantum superposition states in very much the same spirit as the original Schrodinger's cat "gedanken" paradigm. We anticipate our essay to be a starting point to experimentally address fundamental questions, such as the role of life in quantum mechanics, and differences between many-world and Copenhagen interpretations.