11:00 am–12:00 pm
Please Join us:
Ankur Agrawal's PhD Thesis Defense
Tuesday September 6, 2022 at 11:00 am CDT
SUPERCONDUCTING QUBIT ADVANTAGE FOR DARK MATTER (SQuAD)
Dark matter is the most enduring mystery of the universe which has puzzled scientists for almost a century. It comprises almost 25% of the total mass in the universe but remains hypothetical so far. We are interested in low-mass bosonic dark matter candidates - axions and hidden photons which rarely convert into a photon when resonantly captured using a microwave cavity. Current dark matter experiments operating in the GHz frequency range are limited by the increasing amplifier noise and plummeting signal rate as we move to higher frequencies. In this work, I will present three complementary techniques to tackle these challenges. First, I will discuss a novel photon counting technique using superconducting qubits to evade the Standard Quantum Limit (SQL) and bring down the noise level by a factor of 2700x. By preparing the cavity in n=4 Fock state, I demonstrate a 2.5x signal enhancement via stimulated emission as compared to the cavity prepared in its ground state. Finally, I show a novel photonic bandgap axion haloscope which is compatible with a large magnetic field and has a high Q-factor (Q>1 Million), almost 50 times higher than a copper cavity. With a cohesive approach incorporating all the described techniques, the future dark matter searches will be able to scan a wide range of masses at a rate 10,000x faster than conventional methods.
Committee Members:
Aaron Chou (Chair)
David Schuster
Stephan Meyer
LianTao Wang
Ankur will be joining the AWS Center for Quantum Networking as a Quantum Research Scientist.