BALANCE-EQUATIONS FOR ELECTRON-TRANSPORT IN AN ARBITRARY ENERGY-BAND DRIVEN BY AN INTENSE TERAHERTZ FIELD - APPLICATION TO SUPERLATTICE MINIBAND TRANSPORT

We suggest a balance-equation approach to hot-electron transport in a single arbitrary energy band subject to an intense radiation field of terahertz (THz) frequency, including all the multiphoton emission and absorption processes and taking account of realistic scatterings due t o impurities and phonons. This approach, which allows one to calculate THz-driving, time-averaging transport based on a set of time-independ ent equations, provides a convenient method to study the effect of an intense THz electric field on carrier transport in a nonparabolic ener gy band. As an example, these fully three-dimensional, acceleration-an d energy-balance equations are applied to the discussion of superlatti ce miniband transport at lattice temperature T = 77 and 300 K driven b y the THz radiation field of varying strengths. It is shown that the c urrent through a de biased miniband superlattice is greatly reduced by the irradiation of an intense THz electric field.