Researchers at Penn State apply a version of Maxwell’s Demon to reducing entropy in a 3D lattice of super-cooled, laser-trapped atoms
Quantum computers could be built by reducing entropy in a 3D lattice of super-cooled, laser-trapped atoms. A randomly distributed array of atoms were rearranged into neatly organized blocks by researchers at Penn State. This function was described by physicist James Clerk Maxwell in 1870 in a thought experiment famously known as Maxwell’s Demon, which challenged the second law of thermodynamics. A quantum computer that uses uncharged atoms to encode data and perform calculations could be built on the basis of these organized blocks of atoms. The research was published in the journal Nature on September 06, 2018.
Conventional computers depend on transistors to encode data as bits, whereas quantum computers could use atoms as quantum bits. Quantum bits or qubits could encode data with the help of quantum mechanical phenomena, which allows qubits to be present in multiple states simultaneously. A large number of atoms could fit in small areas when these atoms are organized into a packed 3D grid. Such arrangement facilitates easier and more efficient computation as compared to conventional computers. The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time. This law precludes the possibility of a perpetual motion device. Maxwell, in 1870, proposed a thought experiment in which a demon could open and close a gate between two chambers of gas. The imaginary gate allows warmer atoms to pass in one direction and cooler atoms to pass in the other. Such sorting that requires no energy input results in reduction of entropy in the system. The temperature difference between the two chambers could then be used as a heat pump to perform work, which in turn violates the second law of thermodynamics.