Dark Matter Day Seminar Series
Talk 1: Unlocking the Mysteries of Dark Matter and Neutrinos with PandaX
by Prof. Jianglai Liu from Tsung-Dao Lee Institute (TDLI)
Abstract:
Dark matter and neutrinos are elusive, neutral components of the Universe that continue to intrigue us. Is dark matter composed of fundamental particles? How does it interact with ordinary matter? Are neutrinos their own antiparticles? Despite decades of dedicated research, these questions remain unanswered. Over the past two decades, ultra-low-background liquid xenon detectors have emerged as a highly promising technology for probing these mysteries. The PandaX (Particle and Astrophysical Xenon) experiment, located in the China Jinping Underground Laboratory beneath 2,400 meters of rock, is at the forefront of global efforts. Recently, the PandaX-4T detector achieved a significant milestone: a first glimpse of solar neutrinos. In this talk, after an overview of this field, I will provide an overall picture of the PandaX experiment, highlight recent findings, and discuss future prospects for this exciting field.
About the Speaker:
Jianglai Liu earned his B.S. in Physics from Nanjing University in 1998 and completed his Ph.D. in Physics at the University of Maryland in 2006. From 2006 to 2010, he held postdoctoral and then senior postdoctoral scholar positions at Caltech. In 2010, he joined the School of Physics and Astronomy (SPA) at Shanghai Jiao Tong University, where he became a full professor in 2016. He currently serves as the Deputy Director of the Tsung-Dao Lee Institute (TDLI), and is a Hongwen Distinguished Professor jointly appointed between TDLI and SPA. Jianglai Liu has contributed to a variety of experiments at the intersection of nuclear physics, particle physics, and astrophysics. He is the spokesperson for the PandaX experiment, a xenon-based dark matter and neutrino detection project at the China Jinping Underground Laboratory. In 2015, he was awarded the Outstanding Junior Investigator grant by the National Natural Science Foundation of China. He also received the Wang Ganchang Prize from the Chinese Physics Society and the Xplorer Prize from the Tencent Foundation in 2019. Since 2023, he has been supported as a New Cornerstone Investigator (www.newcornerstone.org.cn).
Talk 2: Simulating Axion Electrodynamics in Photonic Crystals
by Prof. Zhang Baile from Nanyang Technological University (SPMS)
Abstract:
Axions were originally proposed to resolve the strong CP problem in particle physics and have since emerged as leading candidates for dark matter. Interestingly, axion electrodynamics also arises in condensed matter systems, where an additional term in the electromagnetic Lagrangian describes the coupling between electric and magnetic fields. In this talk, I will discuss how photonic crystals provide a versatile platform for simulating axion electrodynamics in the laboratory. By engineering the electromagnetic properties and topology of photonic band structures, we can realize effective axion responses and explore their unusual consequences for light propagation and electromagnetic interactions. These experiments establish a connection between topological photonics and axion physics, opening opportunities to investigate axion-related phenomena in controllable photonic systems.
About the Speaker:
Baile Zhang is a Professor of Physics at Nanyang Technological University (NTU), Singapore. His research focuses on wave physics, metamaterials, and topological photonics, with particular interests in exploring fundamental physical phenomena using engineered electromagnetic and acoustic systems. His work has contributed to the development of transformation optics, topological wave phenomena, and photonic realizations of exotic electromagnetic responses, including axion electrodynamics. His research has been published in leading journals, including Nature, Science, and Physical Review Letters.
Talk 3: Searching for Ultraheavy Dark Matter with Magnetically Levitated Sensors
by Asst. Prof. Qin Juehang from Nanyang Technological University (NIE)
Abstract:
There are numerous theoretical candidates for dark matter significantly heavier than the WIMP scale (~100GeV), yet such models are less explored by experimental efforts. In this talk, I will discuss the first search for dark matter above 1 PeV in mass using a magnetically levitated sensor. We set leading constraints on the dark matter-neutron cross section for composite dark matter. Our results extend levitated sensing beyond the mass reach of optical levitation by seven orders of magnitude into the ultraheavy dark matter regime.
About the Speaker:
Qin Juehang is an Assistant Professor in the Natural Sciences and Science Education department at the National Institute of Education, Nanyang Technological University, Singapore. He is an experimental particle physicist, and focuses on searches for dark matter using liquid xenon detectors and quantum and mechanical sensors, and develops machine-learning methods for statistical inference in rare-event searches. He is a member of XENONnT, RELICS, and POLONAISE collaborations.
Talk 4: Hunting for Dark Matter from Singapore with AI: GNOME and Beyond
by Dr. Wang Tao from A*STAR
Abstract:
Dark matter outweighs ordinary matter about five to one, yet its nature remains unknown. If it includes ultralight axion-like fields, Earth’s passage through dark-matter structures could nudge atomic spins as if a tiny magnetic field were present. The Global Network of Optical Magnetometers for Exotic physics searches (GNOME) hunts for these signals with GPS-synchronized, shielded atomic magnetometers around the world. It uses correlations between stations to separate global events from local noise.
This talk introduces the physics behind GNOME and Singapore’s new station, then looks beyond today’s network. New sensors, such as an ultrafast Meissner-levitated spinning rotor above a superconductor, promise greater sensitivity. A hybrid Singapore network linking magnetometers, atomic clocks and gravimeters opens the way to “exotic” multimessenger astronomy. AI ties these data streams together. Transformer-based unsupervised anomaly detection learns the network’s normal behaviour, flags unusual events, and helps sort them into instrumental glitches, environmental effects or possible new physics.
About the Speaker:
Dr. Tao Wang is a Senior Scientist II and Group Leader at the Quantum Innovation Centre (Q.InC), A*STAR. He earned his Ph.D. in Precision Instruments from Beihang University, where he developed ultra-sensitive SERF atomic magnetometers. He then held postdoctoral positions with Prof. Dmitry Budker at UC Berkeley and Prof. Michael Romalis at Princeton University.
His current research combines atomic physics, precision engineering, and AI to develop deployable quantum sensors for applications including dark matter exploration. He has demonstrated the fastest magnetically levitated rotor reported to date, which reaches 138 million RPM. He holds one U.S. patent, has one Singapore patent application pending, and has secured major funding as PI and Co-PI, including a S$13 million CRP project (Co-PI) on next-generation quantum sensing.