Andi Tan



Andi Tan is a Dicke postdoctoral fellow in the Princeton physics department. His research interest is in experiments addressing crucial questions about the dark matter particle and neutrino physics.

Problems of neutrino properties are promising as a portal to discover new physics beyond the Standard Model. As neutrinos rarely interact with matter, the relic neutrinos, the Cosmic Neutrino Background (CNB) decoupled from matter only about a second after the Big Bang, are still ubiquitous. The Hubble expansion, the Big Bang Nucleosynthesis, and the Cosmic Microwave Background had provided evidence of the dynamics of the Universe in great detail back to the epoch when matter and radiation decoupled some 380,000 years after the Big Bang. The direct detection of the CNB would profoundly extend the precision cosmology measurement. As CNB cooled with the expanding Universe, the smaller energy makes their detection even more challenging.

At Princeton, Andi joined the PTOLEMY collaboration lead by Professor Tully, focusing on the detection of the CNB with novel experimental technologies. The Princeton Tritium Observatory for Light, Early-Universe, Massive-Neutrino Yield (PTOLEMY) will explore surface target with tritiated radio-pure graphene for the capture of the relic neutrinos. The electrons emitted by the neutrino capture process on tritium atoms with excessive kinetic energy will pass a high-precision electromagnetic filter and be detected by a high-resolution calorimeter using Transition Edge Sensors (TES). PTOLEMY also exploits a concurrent program in MeV dark matter searches using Graphene Field Effect Transistors (G-FETs). The scattering of MeV dark matter on the graphene target will liberate an electron that would be tracked by G- FETs with tunable meV band gaps. PTOLEMY embraces a diverse physics program from neutrino masses to sterile neutrino searches and leveraging graphene for future dark matter detection concepts.

Andi earned his Ph.D. from the University of Maryland, College Park, where he worked on the direct detection of dark matter particles on the Particle and Astrophysical Xenon (PandaX) project.