Jul 2 2019
Jigang Wang from Iowa State University patiently described his most recent finding in quantum control that could result in superfast computing based on quantum mechanics—he cited light-induced superconductivity without energy gap.
He discussed forbidden supercurrent quantum beats, and talked about terahertz-speed symmetry breaking. Later, he supported and explained everything. Ultimately, the quantum world of matter and energy at terahertz scale and nanometer scale—trillions of cycles per second and billionths of meters—is still unknown to a majority of people.
I like to study quantum control of superconductivity exceeding the gigahertz, or billions of cycles per second, bottleneck in current state-of-the-art quantum computation applications. We’re using terahertz light as a control knob to accelerate supercurrents.
Jigang Wang, Professor, Department of Physics and Astronomy, Iowa State University
Wang’s work has been supported by the Army Research Office.
Superconductivity is defined as the movement of electricity through particular materials without resistance. It usually takes place at tremendously cold temperatures. Consider –400 ○F for “high-temperature” superconductors.
Terahertz light, in essence, is the light at extremely high frequencies. Assume trillions of cycles per second. It is basically very strong and powerful microwave bursts firing at extremely short time frames.
Wang and a group of scientists showed that such light can be used to control some of the important quantum properties of superconducting states, such as broken symmetry, macroscopic supercurrent flowing, and accessing some extremely high-frequency quantum oscillations assumed to be prohibited by symmetry.
It all seems bizarre and mysterious; however, it could have very practical applications.
“Light-induced supercurrents chart a path forward for electromagnetic design of emergent materials properties and collective coherent oscillations for quantum engineering applications,” Wang and a number of co-authors cited in a research paper recently published online by the journal Nature Photonics.
Simply put, the discovery could help physicists “create crazy-fast quantum computers by nudging supercurrents,” Wang wrote in a review of the research group’s discoveries.
At present, finding ways to control, access, and manipulate the unique properties of the quantum world and relate them with real-world issues is a chief scientific drive. The National Science Foundation has added the “Quantum Leap” in its “10 big ideas” for imminent research and development.
“By exploiting interactions of these quantum systems, next-generation technologies for sensing, computing, modeling and communicating will be more accurate and efficient,” states a review of the science foundation’s support of quantum studies. “To reach these capabilities, researchers need understanding of quantum mechanics to observe, manipulate and control the behavior of particles and energy at dimensions at least a million times smaller than the width of a human hair.”
Wang and his partners—Xu Yang, Chirag Vaswani, and Liang Luo from Iowa State, responsible for terahertz experiments and instrumentation; Chris Sundahl, Jong-Hoon Kang and Chang-Beom Eom from the University of Wisconsin-Madison, responsible for high-quality superconducting materials and their characterizations; Martin Mootz and Ilias E. Perakis from the University of Alabama at Birmingham, responsible for model building and hypothetical simulations—are progressing the quantum frontier by discovering new macroscopic supercurrent flowing states and creating quantum controls for changing and modulating them.
A review of the research carried out by the team of scientists reports that experimental data acquired from a terahertz spectroscopy instrument denotes that terahertz light-wave tuning of supercurrents is a universal tool “and is key for pushing quantum functionalities to reach their ultimate limits in many cross-cutting disciplines” like those stated by the science foundation.
Therefore, the scientists wrote, “We believe that it is fair to say that the present study opens a new arena of light-wave superconducting electronics via terahertz quantum control for many years to come.”