An infinite number of quantum particles give clues to large-scale global behavior

In quantum mechanics, the Heisenberg Uncertainty Principle prevents an external observer from measuring both the position and the velocity (called momentum) of a particle. They can not know with a high degree of certainty neither of them – unlike what happens on a large scale where both are known. To identify the characteristics of a given particle, physicists have introduced the concept of quasi-distribution of position and moment. This approach aimed to reconcile the quantum scale interpretation of what is happening in particles with the standard approach used to understand motion on the normal scale, a domain called classical mechanics. .

In a new study published in EPJ STDr. J.S. Ben-Benjamin and colleagues at Texas A & M University, United States, reverse this approach; beginning with the rules of quantum mechanics, they explore how to derive an infinite number of quasi-distributions to mimic the approach of classical mechanics. This approach is also applicable to a number of other variables found in particles at the quantum scale, including the spin of particles.

For example, such quasi-position and pulse distributions can be used to calculate the quantum version of the characteristics of a gas, called the second virial coefficient, and extend it to deduce an infinite number, so as to verify whether it corresponds to the traditional expression of this physical entity as a joint distribution of position and moment in classical mechanics.

This approach is so robust that it can be used to replace quasi-position and momentum distributions with time and frequency distributions. The authors note that this works for both well-defined scenarios in which quasi-time and frequency distributions are known, as well as for random cases where the mean time and frequency average are used.