DCMPMS Seminars

Quantum Hamiltonian Engineering with parametric drives

by Prof. Michael Hatridge (University of Pittsburgh,USA)

Tuesday, June 12, 2018 from to (Asia/Kolkata)
at AG69
Description
One prerequisite for the construction of large-scale quantum machines is rapid, high fidelity qubit measurement. This challenge is now regularly met in superconducting qubits read out with parametrically driven microwave amplifiers. However, their near-quantum limited performance comes at the cost of virtually every other performance metric, including dynamic range, bandwidth, and directionality. In recent work, we have demonstrated the role played by fourth-order Kerr nonlinearities in shifting mode frequency with input power [1] and thus limiting device dynamic range. I will present new results demonstrating our ability to cancel these terms by shunting the Josephson junctions in the three-mode Josephson Parametric Converter (JPC) [2]. I will also discuss how multiply parametrically pumping this device, as recently proposed by Metelmann et al.[3], can result in a new form of amplification which is both directional, has higher saturation powers, and a fixed, broad bandwidth.

[1] Liu, et al. Appl. Phys. Lett. 111, 202603 (2017).
[2] Bergeal, et al. Nat. Phys. 6, 296 (2010).
[3] Metelmann and Clark, Phys. Rev. X 5, 021025 (2015)
Prof. Michael Hatridge is Assistant Professor of Physics at University of Pittsburgh, Pittsburgh, PA, USA

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Michael received a B.S. in physics from Texas A&M University in 2004 and a PhD in condensed matter physics from Berkeley in 2010. From 2010-2015 he was a postdoctoral associate in QLab at Yale University, working under the supervision of Michel Devoret. He is the recipient of the 2015 Michelson Postdoctoral Prize Lectureship.

He is a leader in the development of parametric amplifiers and efficient quantum measurement. His current research focuses on remote quantum interactions via flying qubits.