UNC-CH Physics and Astronomy Colloquium
Jonathan Baugh, University of Waterloo, CA
“Benchmarking quantum control and developing semiconductor-based quantum devices”
The development of robust, scalable quantum information processors is both an extraordinary opportunity and an extraordinary challenge. Over the past 20 years, significant progress has been made in theory and experiment, including quantum control techniques, understanding realistic noise processes, refining error correction schemes, and advancing physical implementations. The first part of the talk will describe our recent experiments applying randomized benchmarking (RB) techniques to a solid-state qubit in the context of conventional electron spin resonance [1]. While standard RB measures only the average gate fidelity, our modified RB allows for distinguishing between coherent and incoherent noise processes. This is very useful since different strategies are employed to reduce the two kinds of error. The experiments also demonstrate a sophisticated use of control waveforms derived from optimal control theory. The second part of the talk will focus on semiconductor nanoelectronic devices as a basis for electron spin qubits and potentially for topologically protected qubits. Using a silicon MOS-type device, we recently implemented a novel ‘quantum memristor’ based on two capacitively coupled quantum dots [2].

1. G. Feng, J. J. Wallman, B. Buonacorsi, F. H. Cho, D. K. Park, T. Xin, D. Lu, J. Baugh, and R. Laflamme, Phys. Rev. Lett. 117, 260501 (2016).
2. Y. Li, G. W. Holloway, S. C. Benjamin, G. A. D. Briggs, J. Baugh, and J. A. Mol, arXiv:1612.08409 (2016).