EurekAlert February 2, 2021 State-of-the-art LWIR detection technology still suffers from shortcomings such as low photocurrent gain and excess spectral noise. Researchers at Northwestern University used a new approach to design the photodetector using a type-II superlattice, a material system known for its outstanding growth uniformity and exceptional band structure engineering and applied the new material to a heterojunction phototransistor device structure. During testing each part of the photodetector was tuned to use the phototransistor to achieve high optical gain, low noise, and high detectivity. The material’s flexibility allowed for meticulous quantum mechanics-based band structure engineering for the heterostructure design, […]
Tag Archives: Quantum device
New quantum nanodevice can simultaneously act as a heat engine and a refrigerator
Phys.org December 28, 2020 An international team of researchers (Japan, Ukraine, USA – University of Michigan) has experimentally demonstrated the quantum version of the heat engine which uses an electron in a transistor. The electron has two possible energy states. The team could increase or decrease the gap between these energy states by applying an electric field and microwaves. This can be analogous to the periodic expanding–compressing operation of a fluid in a chamber. The device also emitted microwaves when the electron went from the high-energy level to the lower one. By monitoring whether the upper energy level was occupied, […]
Tiny bubbles make a quantum leap
EurekAlert July 13, 2020 An international team of researchers (USA – UC Berkeley, Columbia University, industry, Montana State University, Germany, Japan) found that placing sufficient strain in a 2D material–tungsten diselenide creates localized states that can yield single-photon emitters. The team was able to directly image these states for the first time, revealing that even at room temperature they are highly tunable and act as quantum dots, tightly confined pieces of semiconductors that emit light. Fully tunable, room-temperature single-photon emitters are now within our grasp, paving the way for controllable–and practical quantum photonic devices. These devices can be the foundation […]