大学物理演示实验动感创新教学平台的探索与实践

构建大学物理演示实验教学动感创新性平台,需要合理配置教学内容,完善创新人才培养机制;激发广大师生的创新思维和创新潜能,不断深化大学物理演示实验教学改革的深度和广度,促进课堂、实验教学及科研一体化,使高素质创新人才在培养过程中茁壮成长.     

用于TES测辐射热计的Al/Ti双层薄膜制备及其超导特性研究

本文报道了用于超导TES(Transition Edge Sensor)测辐射热计的Al/Ti双层薄膜制备及其超导特性研究.通过分析Al薄膜表面粗糙度和室温电阻率在不同溅射功率和氩气压力下的变化关系,优化了Al薄膜的制备工艺.使用磁控溅射技术生长了一系列不同厚度的Al/Ti双层薄膜,在氦三制冷机中测量了双层膜的超导特性.测试结果表明,Al/Ti双层薄膜具有良好的超导相变特性,在10μA测试电流下,其相变宽度保持在3mK~6mK范围内,在超导临界温度下电阻对温度的灵敏度参量α在300左右;由于超导邻近效应(Proximity effect),双层薄膜的临界温度可以通过控制Ti薄膜的厚度实现在470mK~800mK温区内的调节.Al/Ti双层薄膜的这些性能满足了制备超导TES测辐射热计的需要.     

Local distinguishability by projective measurement

This paper proves that a set of orthogonal pure states are indistinguishable by restricted local projective measurement and classical communication if the sum of their Schmidt ranks is larger than the dimension of their joint Hilbert space. This result is useful in determining the local distinguishability of quantum states and is stronger in some respects than that of Hayashi et al [Phys. Rev. Lett. 96, 040501]. In addition, it presents a new method to determine the local distinguishability of orthogonal states by projecting measurement operators into their subspaces.     

Optical response of Al/Ti bilayer transition edge sensors

We report the optical response characteristics of Al/Ti bilayer transition edge sensors(TESs), which are mainly comprised of Al/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a3 He sorption refrigerator and the device’s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time(τeff) of the devices at different biases and discussed the dependence of τeffon the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff= 3.9 μs, which indicates a high temperature sensitivity(α = T/R· dR/dT =326). The results also showed that the TES exhibits good linearity under optical pulses of variable widths.