Quantum Nano Collision Seminar Series: Professor Jonathan Baugh

The Waterloo Institute for Nanotechnology (WIN) has launched a new seminar series, Quantum Nano Collision (QNC) Seminar Series, to deepen the engagement of the Waterloo researchers who work at the interface of quantum and nanotechnologies. This seminar series will also provide opportunities for senior graduate students, post-doctoral fellows, and research associates to present their innovative work along with the faculty members to bring together the excitement around these cutting-edge technologies that would shape our future.

The next talk for the QNC Seminar Series will be delivered by Professor Jonathan Baugh.

Registration is required. If you have any questions or issues registering, please contact win-office@uwaterloo.ca 

Single-electron devices and their applications in quantum information

This talk will focus on quantum nanoelectronic devices, built on the versatile platform of the two-dimensional electron gas (2DEG), and some of their applications. Ultra-high mobility AlGaAs/GaAs heterostructures typically contain dopant layers to provide carriers, however, a 2DEG can be electrostatically induced by a top gate in an undoped structure. Dopant-free devices are more challenging to fabricate, but have superior reproducibility and lower disorder. Moreover, they can be ambipolar: both hole (P type) and electron (N type) gases can be induced [1]. We demonstrate the diode behaviour of a lateral PN junction and characterize the electroluminescence that occurs under a sufficient PN bias voltage. We also demonstrate the first one-parameter single-electron pump (dynamic quantum dot) in undoped GaAs [2], and discuss how it can be used in metrology (defining the Ampere) or be combined with a PN junction to realize a novel on-demand source of single photons. Next, we focus on electron spin qubits in silicon MOS quantum dots, and the prospects for building a large-scale processor. We propose a node/network architecture for implementing surface code quantum error correction. The scheme splits the scalability problem in two parts: inter-node entanglement distribution and intra-node operations [3]. This approach relaxes constraints on wiring densities and allows the co-integration of readout and multiplexing circuits. I will discuss our experimental efforts to simplify the design of Si MOS quantum dots to improve prospects for scalability [4].     

References

1. Effects of biased and unbiased illuminations on dopant-free GaAs/AlGaAs 2DEGs, A. Shetty et al, J. Baugh, Phys. Rev. B 105, 075302 (2022).
2. Non-adiabatic single-electron pump in a dopant-free GaAs/AlGaAs 2DEG. B. Buonacorsi et al, J. Baugh, Applied Physics Letters 119, 114001 (2021). 
3. Network architecture for a topological quantum computer in silicon, B. Buonacorsi et al, J. Baugh, Quantum Science and Technology 4, 025003 (2019).
4. Few-electrode design for silicon MOS quantum dots, E. B. Ramirez, F. Sfigakis, S. Kudva, J. Baugh, Semiconductor Science and Technology 35, 015002 (2019).

Speaker Biography

Jonathan Baugh is a Professor of Chemistry and member of the Institute for Quantum Computing and WIN at the University of Waterloo. His research group investigates the potential of semiconductor nanoelectronics for scalable quantum information processing. Dr. Baugh obtained a PhD in Physics (2001) at the University of North Carolina at Chapel Hill. He did seminal work on nuclear magnetism in quantum dots during postdoctoral studies at the University of Tokyo prior to joining Waterloo as a faculty member in 2007. He has published more than 70 papers across many research areas, including magnetic resonance, quantum control, quantum transport, quantum dots, nanowires, proximity superconductivity, nanomechanics and materials science.