Ultra-high-density phase-change storage and memory

The advancements in, thermal data recording, of phase-change materials, are discussed. In optical storage, the heat pulses are realized by a sharply focused laser diode, and during read-out the state of the recorded bits is sensed optically, using the same laser at a lower power. The current phase-change memory designs are based on current-induced switching, where the phase-change material is directly Joule heated. The storage density is limited by the diffraction of the laser which prevents improvements in the future. To have storage densities, the reverse amortization process needs higher temperature gradients. The all-thermal concept for phase change storage/memory is a concept to counter the diffraction limit of conventional optical recording.