Title: Next  Frontier in  Quantum Semiconductor science and technology

Abstract: TBD

Biography:

Manijeh Razeghi is one of the leading researchers in the field of optoelectronics. Her areas of expertise are in the growth and characterization techniques for III-V and II-VI semiconductor heterojunction multiple quantum well devices and superlattices for photonic and electronic devices. She was responsible for the design and implementation of epitaxial growth techniques such as metalorganic chemical vapor deposition (MOCVD), VPE, MBE and metalorganic molecular beam epitaxy (MOMBE) as well as optical, electrical, and structural characterization of the semiconductor multilayers. She has developed a number of semiconductors, advanced photonic and electronic devices such as lasers, photodetectors, transistors and which are in turn used in fiber optics communication.

Title: Fast and sensitive bolometric terahertz detection at room temperature through thermomechanical transduction

Abstract:

Utilizing a thermomechanical transduction scheme, we have developed an uncooled, sensitive, and fast THz bolometer by using a doubly clamped GaAs MEMS beam resonator as a sensitive thermistor.  Owing to its ultra-high temperature sensitivity (the noise equivalent temperature difference of ~1 μK/√Hz), the present MEMS bolometer achieves not only a high sensitivity but also an operation bandwidth of several kHz, which is ~100 times faster than other uncooled THz thermal sensors.  The MEMS bolometers are fabricated by the standard semiconductor fabrication processes and are well suited for making detector arrays for realizing THz cameras.

This work has been supported by SCOPE program of Ministry of Internal Affairs and Communications (#JP225006001), A-STEP program from Japan Science and Technology Agency, and KAKENHI B from Japan Society for the Promotion of Science.

Biography:

Kazuhiko Hirakawa received the B.E., M.E., and Ph.D. degrees in electronic engineering in 1982, 1984, and 1987, respectively, from University of Tokyo.  He is currently a professor at Institute of Industrial Science, University of Tokyo.  He is also serving as a director of Institute for Nano Quantum Information Electronics, University of Tokyo.  He was a visiting researcher at Princeton University for 1991-1993 and a visiting professor at Physics Department, Ecole Normale Superieure in 2006.  His current research interests include terahertz dynamics of quantum nanostructures, novel terahertz detection using MEMS resonators, and cooling effect in semiconductor heterostructures.  His honor includes the Japan IBM Prize in 2005, the Quantum Devices Award in 2016, and the Leo Esaki Prize in 2018.

Wei Lu

Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, China

Title: Quantum Well Infrared Detectors for Space Application Prospects with Electro-Optical Joint Manipulation and Beyond

Abstract:

In the field of infrared remote sensing, the technical process involves the transmission of infrared photons, photoelectric detection, electrical signal processing, target recognition, and decision-making. A significant bottleneck from infrared detection to target recognition is the efficient enhancement of the ratio of infrared photoelectrons between targets and non-targets to improve target recognition rates. Addressing this challenge at the pixel level of photoelectric conversion has become a crucial direction in the development of infrared optoelectronic devices. Quantum well infrared photodetectors are particularly suited to this trend, especially in space-to-earth observation applications with strong background infrared radiation.

We have successfully established a quantum well infrared focal plane technology system centered on the joint regulation of light fields and electronic localized states, enabling a new breakthrough in China's space infrared remote sensing technology.

In terms of design principles, we proposed and constructed an infrared detection approach with localized state features. By leveraging new understandings of photoelectric conversion and carrier transport mechanisms, we established a new working mode for the infrared focal plane array that jointly regulates localized and extended states.

In the field of manufacturing process technology, we have successfully overcome key technical challenges in integrating focal plane array processes by utilizing the microcavity control effects based on plasmonics in the application on infrared-sensitive elements. We have produced three types of quantum well long-wave infrared focal planes—spectral, intensity, and polarization—using localized state control, which significantly enhanced the device performance.

In the application verification phase, our spectral-focal plane array technology has been successfully applied to China's remote sensing satellites in 2023. Additionally, our intensity-focal plane array has been used in new technology test satellites. Furthermore, our polarization-focal plane has been applied in unmanned aerial vehicle target recognition field experiments, improving target recognition capabilities by an order of magnitude.

Further, we explored the possibility of forming high-performance detectors based on the physical foundation of strong-field-induced non-equilibrium states. By developing methods to measure electron temperature through the amplitude of random electron motion, we found that under a high electric field of up to 5×105 V/cm, the electron temperature significantly exceeds the lattice temperature, and exhibits quasi-adiabatic transport with nearly zero net energy exchange with phonons on a nanoscale. This type of quasi-adiabatic transport property, verified in the strong electric fields formed by step-like van der Waals heterojunctions, demonstrated the potential to break the limits of carrier transport determined by the detector drift-diffusion model, transitioning photogenerated carrier transport from dissipative to quasi-adiabatic, thereby effectively enhancing photocurrent.

Biography:

Prof. Lu got his bachelor's degree from the Department of physics at Fudan University, and then got his doctoral degree from the Shanghai Institute of Technical Physics, Chinese Academy of Sciences. He worked as a postdoctoral researcher in Technische Universität Braunschweig funed by the Humboldt Research Fellowship. After that, he worked in University of Gothenburg in Sweden, the Australian National University in Australia, Humblodt University of Berlin as a visting professor.

Abstract:

The invention of maser by N. Basov and A. Prokhorov marked the beginning of a laser era. The principle of stimulated emission was brilliantly implemented in microwave radiation in molecular beams. Nowadays, solid state media are used to obtain visible and NIR laser radiation. At the same time, obtaining coherent microwave radiation has been neglected. In recent years, rapid development of molecular crystal growth technology has enabled to describe new mechanisms of maser origin for generating coherent microwave radiation in solid state. In my  lecture I’m going to give the historical overview of the development of ideas in microwave and later THz radiation in solid state. I’ll speak about the unique properties of molecular crystals as if specially created for the development of coherent THz radiation. The special role in such crystals is played by time resolved behavior of phonons and polaritons. In some cases they are capable of emitting electromagnetic radiation, and in some cases even enhance it.  I’ll also discuss the main mechanisms for narrow- and broadband  coherent THz radiation. Sometimes such processes require phase-matching conditions. In the concluding part of the lecture I’ll talk about the application of molecular crystals for the creation of broadband metamaterial-based chemical sensors.

Biography:

Alexander Pavlovich Shkurinov received the master's, Ph.D., and Doctor (Habilitation) degrees in physics and math sciences from M.V. Lomonosov Moscow State University, Moscow, Russia, in 1985, 1988, and 2013, respectively.,Since 2015, he has been a Professor with the Faculty of Physics, MSU. His research interests are mainly centered around the development and application of femtosecond laser techniques, time-resolved spectroscopy of molecules in liquid phase, nonlinear optics, and THz techniques and spectroscopy. He has authored and coauthored more than 300 papers in peer-reviewed scientific journals, and was invited to deliver more than 60 invited lectures and talks. In 2008, the Russian Optical Society awarded him with the medal in honor of Prof. Rozhdestvensky for his contribution into the development of optical science and technology.