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Dephasing Robust Characterization of Qubit Control Noise | Provably Optimal Control for Multiplicative Amplitude Control Noise

Jan 13

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Friday, January 13, 2023 - 2:00pm to 3:00pm


Robert Barr, Johns Hopkins Applied Physics Lab; Colin Trout, Johns Hopkins Applied Physics Lab

The ability to perform fast and robust operations on multi-qubit quantum systems is a necessity for realizing reliable quantum computation. Unfortunately, the inevitable interaction between a quantum system and its environment presents an obstacle for achieving such operations. Despite this challenge, when used in tandem, quantum noise characterization and quantum control provide a means for engineering targeted control protocols that achieve noise-robust quantum logic operations informed by knowledge of the underlying noise properties. In this talk, we specifically focus on the characterization and mitigation of temporally correlated control noise. First, we present recent results on characterizing temporally correlated control noise in the presence of strong dephasing and detuning noise. Through the use of filter design methods, we will show that one can design control waveforms that combine attributes of noise characterization sequences with attributes of noise suppression sequences. Second, we demonstrate an approach for engineering quantum control that optimally mitigates temporally-correlated control noise. Our approach takes the characterization of the control noise as input and utilizes model-based descriptions of the noisy dynamics to frame the search for control solutions as a convex gate-based circuit optimization. When used in concert, the presented characterization and control protocols enable improved estimation of control noise power spectra and efficient design of noise-tailored provably optimal control. --- Robert Barr - Robert Barr is a mathematician at JHU/APL working on quantum control and cryptography. They received their M.A. in mathematical physics from Johns Hopkins University in 2018. Their research focuses on robust and scalable quantum noise spectroscopy, as well as computation on encrypted data. --- Colin Trout - Dr. Colin Trout is a theoretical physicist in the REDD Experimental and Computational Physics Group. Dr. Trout received his Ph.D. from the Georgia Institute of Technology in 2017 followed by a Postdoc at Université de Sherbrooke until joining APL near the beginning of 2020. Dr. Trout's research interests are in the area of quantum error correction, fault-tolerant protocols for implementing robust quantum algorithms, and simulation of quantum systems at the error correction scale.