6,025 research outputs found
Release of virtual photon and phonon pairs from qubit-plasmon-phonon ultrastrong coupling system
The most important difference between ultrastrong and non-ultrastrong
coupling regimes is that the ground state contains excitations. We consider a
qubit-plasmon-phonon ultrastrong coupling (USC) system with a three-level atom
coupled to the photon and phonon via its upper two energy levels and show that
spontaneous emission of the atom from its intermediate to its ground state
produces photon and phonon pairs. It is shown that the current system can
produce a strong photon/phonon stream and the atom-phonon coupling plays the
active role, which ensures the experimental detection. The emission spectrum
and various high-order correlation functions confirm the generation of the
pairs of photons and phonons. Our study has important implications for future
research on virtual photon and phonon pairs creation in the ground state of the
USC regime.Comment: 9 pages, 7 figure
Quantum heat valve and entanglement in superconducting resonators
Quantum superconducting circuit with flexible coupler has been a powerful
platform for designing quantum thermal machines. In this letter, we employ the
tunable coupling of two superconducting resonators to realize a heat valve by
modulating magnetic flux using a superconducting quantum interference device
(SQUID). It is shown that a heat valve can be realized in a wide parameter
range. We find a consistent relation between the heat current and quantum
entanglement, which indicates the dominant role of entanglement on the heat
valve. It provides an insightful understanding of quantum features in quantum
heat machines.Comment: 9 figures, 4 figure
Cryopreservation of Orchid Genetic Resources by Desiccation: A Case Study of Bletilla formosana
Many native orchid populations declined yearly due to economic development and climate change. This resulted in some wild orchids being threatened. In order to maintain the orchid genetic resources, development of proper methods for the longâterm preservation is urgent. Low temperature or dry storage methods for the preservation of orchid genetic resources have been implemented but are not effective in maintaining high viability of certain orchids for long periods. Cryopreservation is one of the most acceptable methods for longâterm conservation of plant germplasm. Orchid seeds and pollens are ideal materials for longâterm preservation (seed banking) in liquid nitrogen (LN) as the seeds and pollens are minute, enabling the storage of many hundreds of thousands of seeds or pollens in a small vial, and as most species germinate readily, making the technique very economical. This article describes cryopreservation of orchid genetic resources by desiccation and a case study of Bletilla formosana. We hope to provide a more practical potential cryopreservation method for future research needs
Effect of different a-InGaZnO TFTs channel thickness upon self-heating stress
In this work, Indium-Galium-Zinc-Oxide Thin Film Transistors (IGZO TFTs) with different channel thickness has been compared after self-heating stress (SHS). In previous literatures, self-heating of TFTs has been widely discussed and Joule Heat caused during driving TFTs has been compared with different channel length and width [1]. However, different channel thickness hasnât been investigated. Although TFTs with a larger channel thickness possess a greater drain current, a less degradation is observed when comparing with small channel thickness structures, demonstrated in Figure 1(a). The ÎVt shift in the transfer characteristics are well described by the stretched-exponential equation. The EÏ value, which is the average effective barrier height for electron transport, is extracted in Figure (b). Results has shown that in the thick IGZO TFTs, the value is almost twice of that in the thin IGZO TFTs. From COMSOL simulations demonstrated in Figure 1(c), in could be noticed that different channel thickness effects the electrical field locating at the gate insulator. Therefore, a model is proposed to explain the degradation difference, illustrated in Figure (4).
Please click Additional Files below to see the full abstract
- âŠ