Quantum information science with superconducting artificial atoms


Dr. William D. Oliver, MIT Lincoln Laboratory and the Research Laboratory of Electronics -- 06-02-2014


Superconducting qubits are electronic circuits comprising lithographically defined Josephson junctions, inductors, capacitors, and interconnects. When cooled to dilution refrigerator temperatures, these circuits behave as quantum mechanical “artificial atoms,” exhibiting quantized states of electric charge, magnetic flux, or junction phase depending on the design parameters of the constituent circuit elements. Their potential for lithographic scalability, compatibility with microwave control, and high-fidelity operability at nanosecond timescales place superconducting qubits among the leading modalities being considered for quantum information science and technology applications. 

This talk begins with an overview of quantum information science and superconducting artificial atoms.  We review our recent results from a highly coherent 2D transmons, 3D transmons, and persistent-current flux qubits, achieving single-qubit gate fidelities (randomized benchmarking) as high as 99.8% [1]. We have investigated noise and its mitigation during free and driven evolution using dynamical decoupling [2], rotary echo [3] and spin-locking [4] techniques. 

In addition to such fundamental studies of quantum coherence, we are engineering several classical control [5] and amplifier [6,7] technologies aimed at facilitating the quantum-to-classical interface. We will discuss these and related foundational aspects (materials, fabrication, process control, …) [8] in the context of superconducting qubits as these devices transition from the realm of scientific curiosity to the threshold of technical reality.

[1] J. Bylander, et al., Nature Physics 7, 565 (2011)
[2] S. Gustavsson, et al., PRL 108, 170503 (2012)
[3] S. Gustavsson, et al., PRL 110, 040502 (2013)
[4] F. Yan, et al., Nature Comm. 4, 2337 (2013)
[5] S. Tolpygo et al., arXiv:1309.7505 (2013)
[6] Z. Lin et al., APL 103, 132602 (2013); 
[7] C. Maklin et al., APS March meeting (2014)
[8] W.D. Oliver and P.B. Welander, MRS Bulletin, 38, 816-825 (2013)


William (Will) Oliver is an electrical engineer and experimental condensed matter physicist. He is a Senior Staff Member of the Advanced Technology Division at MIT Lincoln Laboratory and a Research Affiliate with the Orlando Group at the MIT Research Laboratory of Electronics. He is responsible for programmatic development and technical leadership of the superconducting quantum information science programs within these groups. 

Will received a B.S. in Electrical Engineering and a B.A. in Japanese (summa cum laude) from the University of Rochester in 1995; a S.M. degree in Electrical Engineering and Computer Science from MIT in 1997; and a PhD degree in Electrical Engineering from Stanford University in 2003. At Stanford, Will studied quantum noise, quantum optics, and the generation and detection of electron entanglement in low-dimensional nanostructures. His present interests span high-performance classical and quantum information processing, including the materials, fabrication, design, and control of scalable, high-coherence superconducting qubits.

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