The Institute for Quantum Computing (IQC) held its first Quantum Frontiers Distinguished Lecture of the year on Thursday, March 20. John R. Kirtley, physical research science associate at the Center for Probing the Nanoscale in the Department of Applied Physics at Stanford University, was the guest speaker at this event.
Kirtley, a condensed matter physicist, is known for developing novel techniques based on scanning Superconducting Quantum Interference Device (SQUID) microscopy. He is a Fellow of the American Physical Society (APS) and the American Association for the Advancement of Science. He was co-recipient of the 1998 Oliver E. Buckley Prize in Condensed Matter Physics.
His lecture explored the results of research conducted at Stanford, led by Kathryn A. Moler, published in March of 2013: Scanning SQUID Microscopy of Topological Insulators.
A powerful tool for measuring really small magnetic fields, the scanning SQUID microscope is used in imaging fields above sample surfaces. Magnetic imaging of short circuits in integrated circuits, corrosion currents in aluminum, and trapped flux in superconductors are among its many varied uses.
Topological insulators (TI) are recently discovered materials that under certain conditions are insulating in the bulk but conducting on their surfaces with quantized, spin polarized currents. Proximity of a topological insulator to a superconductor (S) is predicted to give rise to exotic quantum phenomena and unconventional electrical properties.
The research team used a scanning SQUID microscope to image the bulk and edge currents in mercury telleride (HgTe) quantum well, one of few known topological insulators. They also performed a series of experiments under varied electrical and temperature conditions, which provide great insights into the electronic behaviour of such materials.
IQC’s Quantum Frontier Distinguished Lecture series was created in 2011 to bring scientists at the forefront of quantum research to Waterloo and to explore the many ways quantum mechanics can be harnessed and exploited to transform science and society.
