2017/10/31 by Paul S. Davids, Paul Davids, Joshua Shank · 13 citations
Computer Science · Physics and Astronomy · #Condensed matter physics #Density matrix #Density of states #Hamiltonian (control theory) #Photon #Photon polarization #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum electrodynamics #Quantum mechanics #Quantum tunnelling #Semiconductor Quantum Structures and Devices #Transfer matrix #Wave function #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.97.075411
published in Physical review. B./Physical review. B 97(7) (American Physical Society) · 8 pages, 2 figures
arxiv created 2018/01/08 · openalex publication_date 2018/02/09 · arxiv updated 2018/02/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The transfer Hamiltonian tunneling current is derived in a time-dependent density matrix formulation and is used to examine photon-assisted tunneling. Bardeen's tunneling expression arises as the result of first-order perturbation theory in a mean-field expansion of the density matrix. Photon-assisted tunneling from confined electromagnetic fields in the forbidden tunnel barrier region occurs due to time-varying polarization and wave-function overlap in the gap which leads to a nonzero tunneling current in asymmetric device structures, even in an unbiased state. The photon energy is seen to act as an effective temperature-dependent bias in a uniform barrier asymmetric tunneling example problem. Higher-order terms in the density matrix expansion give rise to multiphoton enhanced tunneling currents that can be considered an extension of nonlinear optics where the nonlinear conductance plays a similar role as the nonlinear susceptibilities in the continuity equations.