Negative absolute temperature device

We can create a device that cools air to negative absolute temperature by placing an upper limit to kinetic energy, potential energy and interaction energy.

By inserting air into a cavity in which we produce an optical stationary wave by interfering a laser beam of wavelength 736 nm with its reflection. This stationary wave places an upper limit to the kinetic energy of the air molecules by placing all of them into a collective valence band separated by a bandgap from a conduction band.

In a metal cavity, a laser beam and its reflection interfere forming a standing wave

By subjecting the air molecules to a magnetic field of 402,5 Gauss, we create attractive interactions using Feshbach resonance with the magnetic field between the air molecules. These attractive interactions place an upper limit to the interaction energy.

By subjecting the air molecules to an optical stationary wave produced by interfering a laser beam of 271 Hz with its reflection, we create an anti-trap potential, an unstable potential hill. This places an upper limit to the potential energy.

When we have all these upper limits placed on all of these forms of energy and we continue adding heat to the air molecules, all the molecules will enter the same quantum state of the upper energy value and create a Bose-Einstein condensate with negative absolute temperature.

When most of the particles are found at the top of the valence band and there is a large bandgap separating the valence band from the conduction band, the gas is at negative absolute temperature