Using ultrafast pulses of laser light, university researchers were able to create a technique that can record the quantum mechanical behavior of electron in a diamond’s nanoscale defect. The researchers applied these laser light pulses to control the whole quantum state of the nanoscale defect and to observe how a single electron state cahnges over time.
The research, led by the University of Chicago scientists, contributes to the constantly evolving field of quantum information processing, one that demands science to get rid of the “unambiguous universe of traditional binary logic—0 or 1—and embrace the counterintuitive quantum world” wherein electrons can be in several states at once.
They say it could speed up the development of quantum computing devices as well as the additional computing power because materials with appropriate quantum properties will be identified easier. A quantum computer makes use of the electron’s spin state as quantum bit or qubit, similar to how traditional computers apply the electron’s charge state to create specks of information.
The researchers looked into the electron’s quantum mechanical property called spin. The spin system on study is regarded as nitrogen-vacancy center, a defect the size of an atom naturally occurring in diamond, which consists of nitrogen atom found next to a vacant space in the crystal lattice.
Team leader David Awschalom says in a statement that such defects gathered great interest in the previous decade, “providing a test-bed system for developing semiconductor quantum bits as well as nanoscale sensors.”
“Here, we were able to harness light to completely control the quantum state of this defect at extremely high speeds,” says Awschalom, who is the university’s Liew Family Professor of Molecular Engineering.
Co-lead author Lee Bassett says the goal of the team was to push the quantum control limits in such remarkable defect systems and the technique likewise offers a new exciting measurement tool.
“By using pulses of light to direct the defect’s quantum dynamics on super-short timescales, we can extract a wealth of information about the defect and its environment,” says Bassett in a statement.
It also provides a way to understand and control new materials at atomic level, says co-author and professor Guido Burkard, who is also a theoretical physicist at University of Konstanz.
Evelyn Hu, a Harvard University professor, concurs that the new technique developed by the researchers leads to new possibilities.
“Each new system will pose new challenges to understanding the energy levels, local environments and other properties, but the general approach should provide an enormous step forward for the field,” Hu says in a statement.
The paper, titled “Ultrafast optical control of orbital and spin dynamics in a solid-state defect,” appeared this month in the journal Science.
