Physicists were able to implement a copy of Maxwell's famous mental experiment to reduce entropy by creating a system of three-dimensional network of ultra-cooled, laser-encased atoms that can be manipulated and organized in a way that minimizes system entropy. Low introspection can help accelerate progress toward quantum computing .
A team of researchers at the University of Pennsylvania has been able to rearrange a group of atoms randomly distributed in the three-dimensional grid into precisely ordered groups. This is an embodiment of the Maxwell mental experience of the 1870s that challenged (apparently violated) the second law of thermodynamics. The organized masses of atoms form the basis upon which a quantum computer is created that uses uncharged atoms to encode data and perform calculations.
"The traditional (conventional) computers use transistors to encode information as bits that can take one of the values 1 or 2," explains David Weiss, a professor of physics at the University of Pennsylvania who is in charge of the research team. 0, and we are creating quantum computers that use atoms as quantum quantities, which can encode data by taking advantage of the phenomena of quantum mechanics that allow atoms to be in multiple cases at the same time, and allows us to organize atoms in a three-dimensional network to put P A large number of atoms with convenience in a small space, and can make arithmetic easier and more efficient. "
The second law of thermodynamics states that the entropy of a system, which physically expresses chaos in the system, can not diminish over time. One of the results of this law is that it excludes the possibility of a permanent motion apparatus. In 1870, James Clarke Maxwell proposed a mental experiment A "puff" can open and close a gate between two chambers of gas allowing atoms that have greater kinetic energy; that is, their temperature is higher by moving towards and passing atoms that have less kinetic energy; that is, their temperature is lower in the other direction. In addition to the system entropy and temperature differences between the two chambers, which can be used as a heat pump to do work, and then violate the second law we mentioned, Weiss continues: "A subsequent work showed that the" sprite " , And then there have been many attempts to create experimental systems that behave like a sprite, and have achieved some successes on very small scales, but we have created a system by which to manipulate a large number of atoms, and organized in a way that reduces the entropy of the system,
The researchers use lasers to capture and cool atoms in a three-dimensional grid with 125 organized objects in the form of a 5 * 5 * 5 cube, and then fill half of these positions with atoms randomly. Researchers can move the atoms individually or in groups by adjusting the polarization of laser traps, The atoms are randomly distributed to fully fill sub-surfaces of the grid either 5 x 5 x 2 or 4 x 4 x 3, Weiss summarizes the result of the experiment by saying: "The atoms in our experiment are cooled to the lowest possible temperature, the entropy of the system is almost the result Exclusively for the random ordering of atoms within the grid, while doubting For atoms to vibrate in systems where the atoms are not very cold, the majority of the system is entropy. In this case, the arrangement of the atoms will only cause a slight change in the entropy. But in our experiment, the regulation of the atoms - 2.4 ".
Image: Weiss Laboratory, Penn State
Explanation:
Each row shows a snapshot of five levels in the grid. The top row shows the primitive random distribution of atoms between a three-dimensional system with 125 possible positions, while the second row shows the distribution of atoms after order The first and third row are the distribution of atoms after the second order. At this point the target (partial network 5 * 5 * 2) is filled with atoms completely, and this process reduces the entropy in the system by a factor of about 2.4.
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