Can we bring life forms into pure quantum states? Will we ever manage to elevate Schrodinger's cat from thought experiment to real-life experiment?
A recent publication suggests the answers to above questions are affirmative.
In 1935 Erwin Schrodinger proposed a famous thought experiment in which a cat was brought in a coherent quantum state and thereby rendered alive and dead at the same time. Schrodinger used this thought experiment to illustrate conceptual problems in the interpretation of quantum mechanics. In the years thereafter, and in fact throughout the twentieth century, Schrodinger's cat has been subject of various debates and a vast number of scientific studies on the conceptual foundation of quantum mechanics. As a result, Schrodinger's cat has led to
alternative interpretations of quantum mechanics, including the many-worlds interpretation.
Also, Schrodinger's cat became a recurring theme in popular culture and continued to amaze and intrigue not only the general public, but also students of quantum physics. Now, three quarters of a century later, a Spanish-German collaboration is proposing real-life Schrodinger cat experiments.
Animal rights activists need not worry (yet). The goal of the proposed experiments does not involve quantum catslaughter. Initial focus is on bringing nano-sized lifeforms such as viruses into quantum superpositions. This in itself would open up the possibility to observe genuine quantum effects with living organisms. However, these experiments need not be limited to nano-sized organisms, but could be extended to bring larger and more complex living organisms to the quantum realm. Organisms sized up to 1 mm could in principle be brought in quantum superposition. Cat-sized animals, and experiments addressing the role of consciousness in quantum mechanics might not be within immediate reach.
Yet, the proposed experiments – when successful - will be a first step towards such a goal.
The proposed experiments build on recent progress in quantum optomechanics, and involve living organisms such as viruses levitating in vacuum inside an electromagnetic cavity. The fact that these organisms will not be in contact with any mechanical objects should enable so-called ground state cooling and would at the same time avoid decoherence of their quantum states.
Viruses are ideally suited for these experiments not only because they have dielectric properties, but also because their size is comparable to the laser wavelengths used in these quantum optomechanics experiments. Furthermore viruses exhibit high resistance to extreme conditions and can live in low-pressure vacuum. As an example, the common influenza viruses, with a typical size of 100 nm, can be stored for several weeks in deep vacuum.
It is believed that the condition of the microorganism being of size comparable to the wavelength of the light used can be relaxed. This would allow extension to objects larger than the wavelength, and would permit us to bring larger and more complex living organisms to the quantum realm. For instance, the Tardigrade or water bear, with size ranging from 100 μm to about 1.5 mm, is known to survive during several days in open space.
One would assume that in the proposed quantum optomechanic experiments it will not die, but get into a quantum superposition of life and death.
Quantum immortality might be just around the corner.