Science, 202 1, vol. 372, No.6540.
Science, 202 1, vol. 372, No.6540.
Physics physics
Josephson junction infrared single photon detector
Josephson junction infrared single photon detector
Authors: Evan D. Walsh, Wu, Jill, Dmitry K. Evtov, Wu Pei 'an, Huang Kefeng, etc.
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Computers and superconducting quantum computers. Although the performance of the device will be reduced due to the generation of quasi-particles formed by broken Cooper pairs, this phenomenon also provides an opportunity for sensitive detection of electromagnetic radiation. We realize single near-infrared photon detection by coupling photons to local surface plasmon of graphene-based Josephson junction. Using the photon-induced switching statistics of current-based devices, we reveal the key role of quasi-particles generated by absorbed photons in the detection mechanism. Photon sensitivity will provide high-speed and low-power optical interconnection for future superconducting computing architecture.
High-dimensional supersymmetric micro-laser array
High-dimensional supersymmetric micro-laser array
Authors: Xingduqiao, Bikas Karimi Diya, Zi Hegao, Zhao, Tian Weiwu, et al.
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The complexity of increasing the number of components in integrated photonics is the main obstacle to the large-scale phase-locked laser array. Here, we develop a higher dimensional supersymmetric form for accurate mode control and nonlinear power scaling. Our super-symmetric micro-laser array has the phase-locked coherence and synchronization of all evanescent coupling micro-ring lasers-oscillating together in the basic lateral supermodel-which increases the energy density of high radiation, small divergence and single-frequency laser emission by two orders of magnitude. We also demonstrate the feasibility of constructing a vortex laser beam with high emissivity, which can improve the laser performance by making full use of the spatial freedom of light. Our method provides a way to design large-scale integrated photonic systems under classical and quantum mechanisms.
materials science
Broadband directional control of thermal radiation
Broadband directional control of thermal radiation
Authors: Xu Jin, Jyotimoy Mandal, Aaswath P. Raman.
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Compared with the case of "no insurance policy". Negative emission technology plays an important role in achieving near zero emission. By 2050, the carbon captured will account for 20% of the total emission reduction on average. Our multi-model comparison reveals the huge differences in the necessary emission reduction of various departments, and it is consistent that the power sector is required to achieve complete decarbonization by 2050. The cross-model average shows that the cumulative policy cost of China may reach 2.8% to 5.7% of its GDP by 2050, considering the warming limit of 1.5 degrees Celsius.
Global groundwater wells are in danger of drying up.
Groundwater wells around the world are at risk of drying up.
Authors: Scott Jaseko, Debra Peirone,
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Compared with natural immunization and two-dose immunization. Based on the existing immunoepidemiological model, we found that in the short term, focusing on one dose usually reduces infection, but the long-term result depends on this relative immune robustness. Then, we discussed three options, and found that under some conditions of partial population immunity, single dose strategy may increase the possibility of antigen evolution. We emphasize the urgent need to detect the viral load and quantify the immune response after a dose of vaccine, and to increase vaccination efforts around the world.