Near field thermal memory based on radiative phase bistability of VO₂

We report the concept of a near-field memory device based on the radiative bistability effect in the system of two closely separated parallel plates of SiO₂ and VO₂ which exchange heat by thermal radiation in vacuum. We demonstrate that the VO₂ plate, having metal-insulator transition at 340 K, has two thermodynamical steady-states. One can switch between the states using an external laser impulse. We show that due to near-field photon tunneling between the plates, the switching time is found to be only 5 ms which is several orders lower than in case of far field. (paper)