Adrian Lupascu

Professor, Physics and Astronomy

Research interests: quantum computation; superconducting circuits; microwave photons


Biography

Lupascu joined the University of Waterloo in 2010. His research addresses quantum effects in solid state nano-devices, in particular superconductors. These systems have an important potential for applications in quantum information processing. In addition they provide a testbed for fundamental studies of light-matter interaction and quantum detection.

Lupascu obtained his PhD from Delft University of Technology, the Netherlands. His research, done in the Kavli Institute for Nanoscience in the period 2000-2005, focused on experiments with superconducting quantum bits, in particular on the state measurement of such quantum bits. This research established the so-called dispersive readout techniques for qubits and led to the first demonstration of a quantum non-demolition type of measurement for a solid-state qubit. From 2006 to 2009, Lupascu was a postdoctoral researcher at Ecole Normale Supérieure Paris, supported by a Marie Curie fellowship. His research addressed the cooling and trapping of neutral atoms using magnetic traps based on superconductors, a field which brings together atomic and solid state physics. Lupascu also worked on the design and implementation of fast and efficient electron detectors for cryogenic atomic physics experiments, based on a superconducting nanowires.

Education

  • PhD, Delft University of Technology, The Netherlands, 2005
  • BSc, University of Bucharest, Romania, 2000

Awards and Honours

Year Awards and Honours
2018 WIN Research Leaders Award
2011 Early Researcher Award
2011 Sloan Foundation Fellowship
2007 Marie Curie Fellowship

Research

Quantum computing

Quantum effects in superconducting devices arise as a consequence of three properties: low dissipation in the superconducting state, large electron-electron interaction energies in nanostructures, and strong non-linear electrodynamics in nonometer-thick superconducting tunnel barriers. The main goal of this research is finding the best design characteristics which will lead to long quantum coherence times, high-fidelity quantum control, and high-efficiency quantum state readout. The main application of this research is quantum computing – superconducting quantum bits have a clear advantage as far as scalability is concerned when compared to other systems.

Quantum phenomena in nanostructures

Adrian Lupascu is also researching the use of superconducting circuits to explore fundamental questions in quantum optics, related to light-matter interaction and optimized photo-detection. Superconducting quantum devices will also be used as tools for investigation in quantum measurement: in these systems the strength of detection can be controlled, which enables the study of the time dynamics of a measurement. A related research direction is the study, both from a theoretical and experimental point of view, of the limits of detection of classical signals.

Research interests

  • Coherence and control in superconducting devices
  • Quantum electrodynamics with artificial atoms
  • Quantum annealing

Publications

Selected publications

  • "Ultrastrong coupling of a single artificial atom to an electromagnetic continuum in the nonperturbative regime." Forn-Díaz, P., García-Ripoll, J., Peropadre, B. et al. Nature Phys 13,39–43, 2017
  • Deng, Chunqing, Jean-Luc Orgiazzi, Feiruo Shen, Sahel Ashhab, and Adrian Lupascu. "Observation of Floquet states in a strongly driven artificial atom." Physical review letters 115, no. 13, 2015
  • "Ultrasensitive magnetic field detection using a single artificial atom." Bal, Mustafa, Chunqing Deng, Jean-Luc Orgiazzi, F. R. Ong, and Adrian Lupascu. Nat Commun 3,1324, 2012

  • “Selective darkening of degenerate transitions demonstrated with two superconducting quantum bits”, Nature Physics, 6, 763 2010
  • “Bose-Einstein condensation on a superconducting atom chip”,Europhysics Letters, 81, 56004, 2008
  • “Quantum non-demolition measurement of a superconducting two-level system”, Nature Physics, 3, 119, 2007
  • “High-contrast dispersive readout of a superconducting flux qubit using a nonlinear resonator”, Physical Review Letters 96, 127003, 2006
  • “Nondestructive readout for a superconducting flux qubit”, Physical Review Letters, 93, 177006, 2004

Please see Adrian Lupascu's Google Scholar profile for a current list of his peer-reviewed articles.

Contact