School of Physics Spring Colloquium Series- Dr. Konrad Lehnert

Speaker: Dr. Konrad Lehnert

Host: Colin Parker

Title: Building quantum technology from quantum sound

Abstract: Can the position of an ordinary solid object behave quantum mechanically? Indeed, it can. In the past 15 years, a growing number of experimental demonstrations illustrate that the oscillations or vibrations of macroscopic lumps-of-stuff can be quantum mechanically superposed, squeezed, and entangled. This trend is driven partly by an instinct to create ever larger and more tangible states of quantum superposition. But there is also an emerging notion that mechanical systems can provide a useful quantum technology by exploiting the ways in which sound is different than light and electricity. Notably, the speed of sound is 100,000-fold slower than light and sound waves do not propagate through vacuum.

In this talk, I will describe how quantum control is established over mechanical systems, and how this new ability may impact ambitions to process information quantum mechanically. In particular, I will emphasize the potential for mechanical systems to enable the construction of a quantum communication network.

Bio: Konrad W. Lehnert is the Eugene Higgins Professor of Physics at Yale University. He received his Ph. D. in 1999 from the University of California at Santa Barbara and then did post-doctoral work at Yale from 1999-2003. At Yale, he worked with Robert Schoelkopf on qubit structures built from superconducting circuits. In 2003 he joined JILA, a joint institute of the University of Colorado and NIST, as an Associate Fellow. In 2007 he was promoted to JILA Fellow and served as JILA Chair from 2022- 2023, before moving back to Yale in 2024. His research studies microwave quantum circuits, mesoscopic electronics, and quantum nanomechanics. He is a Fellow of the American Physical Society and the American Association for the Advancement of Science. He won the Department of Commerce Silver Medal and the Colorado Governor’s Award for High Impact Research. In 2020, he was awarded a Vannevar Bush Faculty Fellowship.