Transfer Matrix method for computation of electron transmission through aperiodic MQW
This paper presents the Eigen values and corresponding Eigen functions for the electron states in an aperiodic and asymmetric Multiple Quantum Well structure. A faster, simpler, and accurate algorithm based on Transfer Matrix method has been introduced for solving time independent Schrödinger equation in the most general case of aperiodic and asymmetric MQW structure. The MQWs are aperiodic with varying well and barrier widths and asymmetric i.e., having different materials and effective masses for the different regions of the wells and barriers. Adjacent wells are coupled through the barriers. Effect of barrier width on the tunneling properties has also been investigated. The theoretical results are compared with experimental results of Giorgetta et all [1]. Results of the computation based on the general model agree well with experimental data.
Multilayer Josephson Junctions as a Multiple Quantum Well Structure
The macroscopic quantum model in conjunction with the transfer matrix method and Bloch wave analysis have been used to compute the energy dispersion equation for Cooper pairs in finite superconducting quantum well (SQW) structures. The energy dispersion equation has been numerically solved by the Cauchy Integration method to obtain the energy levels of quantum states in SQW. The possibility of energy levels and subbands formation for Cooper pairs within the bulk energy gap has been shown. Energy gap squeezing has been derived when the Bragg condition for Bloch wave number is satisfied.
High-speed infrared detection by uncooled photovoltaic quantum well infrared photodetectors
We have investigated the temporal response of uncooled photovoltaic quantum well infrared photodetectors (PV QWIP) using 2 ps pulses from a free electron laser. We measured rise and fall times of 8 ps and 63 ps, respectively. We have also determined the temperature dependence of the voltage responsivity and resistance of the sample from 70 K to 300 K. Based on these measurements, we discuss the figures of merit of PV QWIPs in a high-bandwidth 50 Ω environment.We have investigated the temporal response of uncooled photovoltaic quantum well infrared photodetectors (PV QWIP) using 2 ps pulses from a free electron laser. We measured rise and fall times of 8 ps and 63 ps, respectively. We have also determined the temperature dependence of the voltage responsivity and resistance of the sample from 70 K to 300 K. Based on these measurements, we discuss the figures of merit of PV QWIPs in a high-bandwidth 50 Ω environment.