News & Events
2024-04-05
The Department of Physics is proud to welcome its newest faculty member:
Assistant Professor Xueyang Song grew up in north China and attended the Asian Physics Olympiad at high school. She got her Bachelor of Science from Peking University, and PhD in physics from Harvard University, under the supervision of Ashvin Vishwanath. Before joining HKUST, she was a Moore postdoctoral fellow at Massachusetts Institute of Technology.
Professor Song is interested in theoretical condensed matter physics, in particular strongly correlated systems where free electron approximation fails. Quantum effects give rise to emergent phenomena there, such as particles with fractional charge and photon-like excitations in solid state systems. The interplay of symmetry, topology and correlations constrains the ground states, dynamics and kinematics of such systems, despite the absence of exact solution on the many-body systems. She studied effective descriptions and physical properties of frustrated magnetic systems, that fail to order at zero temperature. Instead, the magnetic moments conspire to form collective motions that are best captured by fractions of the elementary degrees of freedom and sometimes gauge structures. More recently, she focused on the exotic physics realized in 2d Moire systems, formed by a slight lattice misalignment among multiple atomic-thin layers stacked together. She investigated topological superconductivity and phase transitions relevant to these tunable platforms.
Her research makes extensive use of effective field theory, as well as lattice models, through a combination of analytical and numerical methods.
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2024-02-20
Congratulations to Prof. Kam Tuen Law for being selected to receive the 2023 Achievement in Asia Award (AAA) Robert T. Poe Prize from the International Organization of Chinese Physicists and Astronomers (OCPA). The AAA is presented annually to a physicist/astronomer (or a team of Physicists/astronomers) of Chinese ethnicity working in Asia who has (have) made outstanding contributions in physics or astronomy.
See the School of Science press release for more information.
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2024-01-30
A groundbreaking study spearheaded by a team from The Hong Kong University of Science and Technology (HKUST) led by Prof. C. T. Chan, in collaboration with a team from Fudan University led by Prof. Jian Zi, has been published in Physical Review X. This study, titled "Imaging with an Ultrathin Reciprocal Lens", introduces a paradigm-shifting imaging mechanism—the "reciprocal lens." This novel lens performs imaging by shifting light rays rather than bending them like conventional lenses. It can directly produce upright real images. This research has potential for wide-ranging applications.
Lenses are indispensable in imaging systems. Lenses like those used in optical systems including cameras and microscopes form images by bending light rays entering the lens structure. The rays originating from the object are altered in direction as they pass through the lens. The bent rays converge on a single point on the image plane to reconstruct the object's image. This relies on the lens having varying optical properties and thickness to properly deviate the rays' paths. In recent years, "metalenses" fabricated using micro- and nano- techniques utilize flat nanostructures to control phases and bend rays by imposing phase gradients. However, both conventional and metamaterial lenses share the fundamental mechanism of bending rays (Fig. 1).
The reciprocal lens designed and implemented by the research team enables imaging through a different mechanism than bending rays. It controls the lateral shifts of rays based on their incidence angle (Fig. 1). The lens imposes an angle-dependent phase distribution that causes rays entering at different angles to shift laterally by varying amounts after passing through. This engineered angle-dependent ray shifting makes rays originating from a point source converge after exiting the lens, achieving the imaging functionality. The team utilized geometric optics theory to derive the conditions and phase modulation requirements for reciprocal lens imaging.
Figure 1: Schematics comparing the mechanisms of the reciprocal lens and conventional/metalenses.
For this study, research team members constructed an ultra-thin reciprocal lens operating in the microwave frequency range (28.5 GHz) using standard printed circuit boards (PCB) as shown in Fig. 2a. The lens consists of a core layer featuring a hexagonal lattice of holes and patches, sandwiched by two cladding layers. This structure supports multiple guided resonances that provide the necessary phase modulation effect. The researchers tested the propagation phase through the lens and confirmed it satisfies the phase distribution relationship needed for reciprocal lens imaging. Experiments showed the 1 mm-thick core layer could produce focal lengths on the order of centimeters, enabling imaging (Fig. 2b). The team also tested imaging using objects of various shapes, demonstrating the reciprocal lens's imaging ability without shape constraints.
Figure 2: Imaging of an "F" slit using the PCB-based reciprocal lens shown in (a). The upright real image obtained with the lens shows sharper edges and improved resolution compared to the reference image captured without any lens.
The reciprocal lens realized in this study enables imaging without bending light rays, completely subverting the conventional imaging mechanism and providing a new choice for lens and imaging technologies. The reciprocal lens is ultra-thin and alignment-free, uniquely suited for constrained applications. This research outcome has expanded the theoretical foundations of imaging technology and has also opened up new directions for wavefront modulation.
Research supported by the Research Grants Council of Hong Kong, Croucher Foundation, National Natural Science Foundation of China, and other agencies.
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2023-12-18
The Department of Physics is pleased to announce the winners of the 2023 Paul and May Chu Undergraduate Research Awards. The Paul and May Chu Undergraduate Research Award is awarded to Xuan Tan NGUYEN, and Honorable Mentions are awarded to Zhiwei HE and Cheuk Kan Kelvin YUE. These Awards recognize physics undergraduate students for their outstanding achievements in research in any area.
Xuan Tan NGUYEN
Paul and May Chu Undergraduate Research Award “For contributions to the understanding of the temporal coherence of electron sources in electron microscopy”under the supervision of Prof. Michael S. Altman. Xuan Tan NGUYEN worked on the theory of image formation in electron microscopy under the supervision of Prof. Michael S. Altman for two years beginning in Summer 2021. In his award- winning work, Tan updated the existing theory to accurately describe effects caused by the partial temporal coherence of field emission electron sources commonly used in state-of-the-art instruments. The new insights that this work provided have important implications for optimizing image resolution and for performing advanced image analysis. Tan is the lead author on a paper about this work published in a Q1 topical journal, Ultramicroscopy 252, 113751 (2023). Zhiwei HE
Paul and May Chu Undergraduate Research Award, Honorable Mention “For contributions to research of the High-Temperature-Superconductor YBCO based on NV Centers”under the supervision of Prof. Yang Sen. Zhiwei HE worked on experimental condensed matter physics under the supervision of Prof. Sen Yang since Summer 2021. Zhiwei spearheaded research on pressure driven quantum phase transitions in solid state materials using color centers in diamond. Using a low temperature confocal microscopy system that he built, Zhiwei determined a detailed phase diagram of superconductivity in YBCO under pressure. The rich information obtained in his work advances the understanding of the detailed mechanism of superconductivity in this important material. Cheuk Kan Kelvin YUE
Paul and May Chu Undergraduate Research Award, Honorable Mention “For contributions to validating theoretical calculations with the Monte Carl tool MCFM for the measurement of the W boson mass”under the supervision of Dr. David Walter (CERN). Cheuk Kan Kelvin YUE undertook high energy physics research at the European Organization for Nuclear Research (CERN) under the supervision of Dr. David Walter during Summer 2023. In this project, Kelvin established codes to validate theoretical calculations performed using the “Monte Carlo for FeMtobarn Processes” (MCFM) numerical tool. Importantly, he identified a critical bug in this public program, which is used extensively for calculations on hadronic processes. The validated MCFM predictions can then be employed to reweight Monte Carlo samples, enabling a precise measurement of the W boson mass. Read more
Paul and May Chu Undergraduate Research Award “For contributions to the understanding of the temporal coherence of electron sources in electron microscopy”under the supervision of Prof. Michael S. Altman. Xuan Tan NGUYEN worked on the theory of image formation in electron microscopy under the supervision of Prof. Michael S. Altman for two years beginning in Summer 2021. In his award- winning work, Tan updated the existing theory to accurately describe effects caused by the partial temporal coherence of field emission electron sources commonly used in state-of-the-art instruments. The new insights that this work provided have important implications for optimizing image resolution and for performing advanced image analysis. Tan is the lead author on a paper about this work published in a Q1 topical journal, Ultramicroscopy 252, 113751 (2023). Zhiwei HE
Paul and May Chu Undergraduate Research Award, Honorable Mention “For contributions to research of the High-Temperature-Superconductor YBCO based on NV Centers”under the supervision of Prof. Yang Sen. Zhiwei HE worked on experimental condensed matter physics under the supervision of Prof. Sen Yang since Summer 2021. Zhiwei spearheaded research on pressure driven quantum phase transitions in solid state materials using color centers in diamond. Using a low temperature confocal microscopy system that he built, Zhiwei determined a detailed phase diagram of superconductivity in YBCO under pressure. The rich information obtained in his work advances the understanding of the detailed mechanism of superconductivity in this important material. Cheuk Kan Kelvin YUE
Paul and May Chu Undergraduate Research Award, Honorable Mention “For contributions to validating theoretical calculations with the Monte Carl tool MCFM for the measurement of the W boson mass”under the supervision of Dr. David Walter (CERN). Cheuk Kan Kelvin YUE undertook high energy physics research at the European Organization for Nuclear Research (CERN) under the supervision of Dr. David Walter during Summer 2023. In this project, Kelvin established codes to validate theoretical calculations performed using the “Monte Carlo for FeMtobarn Processes” (MCFM) numerical tool. Importantly, he identified a critical bug in this public program, which is used extensively for calculations on hadronic processes. The validated MCFM predictions can then be employed to reweight Monte Carlo samples, enabling a precise measurement of the W boson mass. Read more
2023-12-18
Congratulations to Assistant Professor Hoi Chun Adrian Po, who was honored with the prestigious Croucher Tak Wah Mak Innovation Award 2023 by the Croucher Foundation for his distinguished research achievements and has been named the Hari Harilela Assistant Professor of Physics by the University.
Prof. Po joined HKUST as an Assistant Professor of Physics in 2021. After obtaining his bachelor’s degree from the Chinese University in 2013, Prof. Po received an M.A. from the University of California, Berkeley and graduated from Harvard University with a Ph.D. in 2018. He was a Pappalardo Postdoctoral Fellow at the Massachusetts Institute of Technology following his graduation until he joined HKUST. Prof. Po is a condensed matter theoretical physicist whose interests broadly lie in the collective phenomena that arise when a large number of quantum particles interact and the intriguing interplay between symmetry, topology, and locality that can arise in quantum materials.
Established in 2012, the Croucher Innovation Awards aim to identify and provide substantial support to small number of exceptionally talented “rising stars” in science and engineering disciplines at a formative stage of their careers. They are one of the Croucher Foundation’s most prestigious awards. With the support provided with this award, Prof. Po will tackle challenging problems concerning the understanding and description of quantum many-body states through the lens of quantum entanglement.
The naming of Prof. Po as the Hari Harilela Assistant Professor of Physics was made possible through the generous support provided by the late Dr. the Honourable Hari N. Harilela, a distinguished Hong Kong Indian entrepreneur and philanthropist. This named professorship recognizes Prof. Po’s achievement in the field of theoretical condensed matter physics in areas ranging from topological materials to out-of-equilibrium quantum dynamics. It will enable Prof. Po to continue his research in the field of condensed matter physics for the betterment of the society.
Press release: Croucher Innovation Award 2023
Press release: Seventh Inauguration Ceremony of Named Professorships
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2023-11-01
Congratulations to Prof. Tai-Kai Ng, Prof. Hoi Chun Adrian Po, and Prof. Penger Tong (l-r) of the Department of Physics for the recognition they received to honor their excellence in research and education.
Prof. Tai-Kai Ng was awarded the Medal of Honour from the Government of the Hong Kong SAR “for his contribution to Gifted Education and STEM Education in Hong Kong”. The Medal of Honour is awarded for community service in a district or in a particular area for a long period of time.
Prof. Hoi Chun Adrian Po and collaborators have been chosen as inaugural recipients of a Frontier of Science Award in the 2023 International Congress of Basic Science. This award recognizes their research work on proposing explicit model and physical mechanism that explain the Mott insulating behavior and superconductivity observed in twisted bilayer graphene.
Prof. Penger Tong was elected as a Fellow of the Physical Society of Hong Kong. The PSHK Fellowship recognizes individuals who have or have been engaged in the community of physical sciences or related fields in Hong Kong and demonstrated exceptional scientific achievements in physics-related research and recognitions by his/her professional peers. Prof. Tong was cited “for his seminal discoveries and exploration of soft matter dynamics and fluid physics and his many contributions to education in experimental physics.”
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2023-10-16
Congratulations to Man Wai Katherine Lai, Yuchen Lin, Duc Huy Tran, Kin To Wong, and Jianhui Zhou (l-r) for being awarded 2023 Academic Achievement Medals. The Academic Achievement Medal is the highest academic honor bestowed by the University on outstanding undergraduate students upon graduation. The awarding of the Medal was established in 1994 to recognize graduates whose outstanding academic achievements bring honor and distinction both to themselves and to the University. Only the top 1% of graduates are awarded the Academic Achievement Medal annually. These awards were presented at the 31st University Congregation on 17 November 2023. The Department is very proud of all graduates and especially delighted in the achievements of the Academic Achievement Medal awardees.
Man Wai Katherine Lai is pursuing her interests in high energy experimental physics as Ph.D. student in the Department of Physics at the University of California, Santa Barbara. Yuchen Lin is pursuing a Ph.D. degree at Columbia University. Duc Huy Tran is pursuing his interest in high energy theoretical physics as a Ph.D. student in the Department of Physics at Harvard University. Kin To Wong is pursuing a Ph.D. degree in Physics at the University of Michigan. Jianhui Zhou is pursuing his interest in condensed matter theoretical physics as an M.Sc. student in the Department of Physics at ETH Zürich.
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2023-09-19
Five exceptional secondary school students from Hong Kong achieved remarkable results at the 53rd International Physics Olympiad (IPhO 2023) held in Tokyo, Japan from 10-17 July 2023. Competing among 394 students from 82 countries or regions, the Hong Kong team, consisting of LAM Chung-Wang (St. Paul’s Co-educational College), HUI Pok Shing (Queen Elizabeth School), KWOK Ching Yeung (S.K.H. Tang Shiu Kin Secondary School), LIU Lincoln (Sha Tin College), and KWOK Tsz Yin (CNEC Christian College), won one gold medal, three silver medals, and one bronze medal. With this outstanding performance, the Hong Kong team was ranked 9th among all teams at the competition. The top ten performance of the team this year and of Hong Kong teams in previous years highlights the passion of local academic talents and the dedication of their mentors. The team was trained and mentored this year by Prof. Jensen Li, Dr. Man Fung Cheung, and Dr. Ting Pong Choy of the HKUST Department of Physics, with the support of the Education Bureau and the Hong Kong Academy for Gifted Education.
The HKUST Department of Physics has been providing training to about 90 secondary school students to prepare for the International Physics Olympiad since 2003 and the Asian Physics Olympiad (APhO) since 2007. The year-long training program offered to these gifted students covers a wide range of topics, from Newtonian mechanics to modern physics, both in theory and experiment. The team members that eventually participate in the IPhO and APhO competitions are chosen based on their performance in a series of selection tests and competitions during their training. The Hong Kong teams under the mentorship of the Department faculty were awarded an aggregate of 142 gold, silver and bronze medals in APhO and IPhO competitions up to and including 2023. Participation in Physics Olympics training and competition develops students’ potential and serves as a springboard for pursuing interests in physics and many other subjects at top universities and beyond.
Accompanying photo (left to right): Dr. Man Fung Cheung (HKUST), Dr. Ting Pong Choy (HKUST), KWOK Ching Yeung, HUI Pok Shing, LAM Chung Wang, LIU Lincoln, KWOK Tsz Yin, and Mr. Chun Keung Ng (physics teacher at Kwai Chung Methodist College).
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2023-09-05
Breakthrough in astroparticle physics lifts undergraduate research to the cutting edge
Prof. Tao Liu and his collaborators, Mr. Xuzixiang LOU (HKUST) and Prof. Jing Ren (Institute of High Energy Physics, Chinese Academy of Sciences, Beijing), recently proposed a pioneering experimental methodology for application in astroparticle physics with potential for far-reaching impact. Based on the observational data for pulsars accumulated over the last few decades, they proposed to construct Pulsar Polarization Arrays to explore new phenomena in astrophysics and fundamental physics. As one scientific case for the use of this new tool, Prof. Liu and his collaboration demonstrated its strong capability to detect ultralight axion-like wave dark matter. The groundbreaking concept of Pulsed Polarization Arrays and its demonstration results were published in the prestigious journal Physical Review Letters [Phys. Rev. Lett. 130, 12401 (2023)] on March 23, 2023.
There are a large number of stably rotating millisecond pulsars in the Milky Way galaxy. These pulsars are known to be extraordinary astronomical clocks and linear polarizers. As astronomical clocks, millisecond pulsars can be used to form a galaxy-scale interferometer, which is called a Pulsar Timing Array (PTA), to detect nano-Hertz gravitational waves (GWs). In pulsar timing observations for detecting the GWs, the polarization of pulses is usually also recorded for calibration purposes. Based on the readily available polarization data accumulated over decades for the PTA programs, Prof. Tao Liu and his collaboration proposed to develop Pulsar Polarization Arrays to give full play to the relevant telescope resources. By cross-correlating the polarization data from the arrayed pulsars, astronomers will be able to explore physics with a common correlated polarization signal at galaxy scale. Using this capability to study the ultralight axion-like wave dark matter as one of the mainstream dark matter candidates is such a scientific target. The ultralight axion-like wave dark matter is characterized by a strong wave nature, due to its de Broglie wavelength of astronomical scale, and meanwhile, can modulate the position angle of linearly polarized pulsar light when it travels across the galactic dark matter halo. The pulsar polarization array is thus especially suited for the detection of ultralight axion-like wave dark matter. Currently, the real data analyses are being either performed or planned in collaboration with several world-leading PTA collaborations, which include the Parkes PTA collaboration (based on the Parkes Radio Telescope) in Australia, the Chinese PTA collaboration (based on the Five Hundred Meter Aperture Spherical Telescope) in China, and the MeerTime collaboration (based on the MeerKAT Radio Telescope) in South Africa.
This research also highlights research opportunities for outstanding undergraduate students. Mr. Xuzixiang LOU, who was a key contributor and co-author of this work, was an student in the elite International Research Enrichment (IRE) undergraduate program at HKUST between 2017 – 2021. Mr. Lou was involved in research projects under Prof. Tao Liu’s close supervision during his second through fourth years of undergraduate study, working on topics ranging from collider physics to dark matter physics. He joined the project on Pulsed Pulsar Arrays in his final undergraduate year and played a key role in advancing this research work. Xuzixiang Lou was awarded the 2021 Academic Achievement Medal at HKUST in recognition of his outstanding academic performance. He will join the high energy physics research group at the State University of New York at Stony Brook as a PhD student in Fall 2023 to continue his study of fundamental physics.
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