Title: From Qubit Control to Hybrid Quantum Interfaces via Nonlinear Couplings

Lecturer: Marios Kounalakis
Affiliation:
Location: Room E130, Dept. of Mathematics' Bldg.
Virtual links: uoc-gr.zoom.us
Time: 16:30
Language: English

Abstract

Realizing scalable quantum technologies requires not only individual quantum systems with long coherence times, but also the ability to couple them together as well as to different physical platforms, in a controlled and tuneable manner. In this talk, I will present my work on harnessing nonlinear interactions to engineer such couplings, from concept to hardware. I will begin with the design, fabrication, and measurement of a tuneable coupler for superconducting qubits, developed from circuit theory through cleanroom fabrication to experimental characterization, enabling on-demand qubit-qubit interactions [1,2]. Building on this, I will discuss theoretical proposals for extending this coupling to realise novel hybrid quantum systems, enabling quantum control of mechanical resonators [3,4] and magnons [5,6]. Such coupling schemes represent a step towards quantum transduction across physical platforms, ultimately bridging microwave-frequency qubits to optical photons for long-distance transmission via nonlinear-optical processes. If time allows, I will also discuss related work applying such nonlinear-optical processes, in particular four-wave mixing, to the direct imaging of shockwave dynamics [7] and its potential extension towards optical probing of other physical systems.

References [1] M. Kounalakis, C Dickel, A Bruno, NK Langford, GA Steele. npj Quantum Information 4, 38 (2018) [2] J.D. Koenig, G. Barbieri, F.F. Sani, C.A. Potts, M. Kounalakis, G.A. Steele. Physical Review Research 8, 013192 (2026) [3] M. Kounalakis, Y.M. Blanter, G.A. Steele. npj Quantum Information 5, 100 (2019) [4] M. Kounalakis, Y.M. Blanter, G.A. Steele. Physical Review Research 2, 023335 (2020) [5] M. Kounalakis, G.E.W. Bauer, Y.M. Blanter. Physical Review Letters 129, 037205 (2022) [6] M. Kounalakis, S. Viola Kusminskiy, Y. M. Blanter. Physical Review B 108, 224416 (2023) [7] M. Kounalakis, M. N. Shneider, A. Gerakis. arXiv:2602.24112

 

Short bio

Born in 1990, in Heraklion, Marios studied physics at the National and Kapodistrian University of Athens, further specialising in Particle Physics with a Master 2 from Paris Diderot University. Excited about Quantum Computing, he later joined the ‘Casimir pre-PhD’ track at Leiden University and wrote a PhD proposal which earned him a fully-funded PhD position at TU Delft's Kavli Institute of Nanoscience. In his thesis, he explored ‘Nonlinear couplings for quantum control of superconducting qubits and electrical/mechanical resonators’. He then held postdoctoral positions at TU Delft and RWTH Aachen, where he developed several theoretical proposals for quantum control in hybrid quantum systems involving magnons and mechanical resonators. He is currently a Senior Scientist at the Luxembourg Institute of Science and Technology, developing lasers and nonlinear-optical techniques for studying high-pressure plasma discharges and transient flow dynamics.

For forthcoming colloquia, please visit: All Colloquia