Nonclassical states of lattice excitations: squeezed and entangled phonons
Institute of Solid State Physics, Russian Academy of Sciences, Akademika Osip'yana str. 2, Chernogolovka, Moscow Region, 142432, Russian Federation
This review considers the theoretical background of and experimental evidence for nonclassical phonon states and has as its primary goal the critical analysis of recent experiments in which squeezed and entangled phonons are created and probed. The quantum aspects of elastic deformation fields similar to nonclassical light fields are of interest for potential use in applied and fundamental research, including quantum computing and testing quantum-theoretical hypotheses.