While most students have no clue what Dirac electrons, quantum computers and copper-doped bismuth selenide are, a new breakthrough by University physicists could eventually change that.
Physics Prof. Lu Li, along with University doctoral student Benjamin Lawson and Yew San Hor, a professor at the Missouri University of Science and Technology, have confirmed that material copper-doped bismuth selenide contains Dirac-like electrons, which could prove significant in increasing the speed and capabilities of quantum computing.
In a typical computer, like the ones students use daily to post on Facebook and work on class assignments, information is stored in a binary format as zeroes and ones, which are called bits. Calculations are performed as different sequences of binary encoding information.
Quantum computers, however, can store these sequences as zeroes and ones separately like a traditional computer, but can also store sequences with both zeroes and ones at the same time, called qubits.
Lawson, who assisted in contrasting the measurement methods and collected much of the project’s data, said the concept could be easily explained by visualizing a device with rows of switches.
“You can think of it like this: I am trying to convey a message to you with a bunch of switches,” Lawson said. “In a classical computer, you look at the switches which are all either up or down and translate a message. In a quantum computer, all the switches are either up, down, or a single switch could be both up and down. With the third option, I can encode much more information with fewer switches.”
The idea of quantum computing is not new — Li said it’s been around for more than a decade. But Li, Lawson and Hor’s recent discovery uncovered the copper-doped bismuth selenide that contains Dirac electrons, or electrons that can outperform regular electrons by allowing “switches” to be up, down or both at the same time.
Lawson compared the material to silicon for classic computers, and said it could be the key building block for quantum computers. Copper-doped bismuth selenide is considered a topological superconductor, meaning they conduct energy indefinitely and have enough energy to process classical and quantum physics.
“That’s the beauty of that scheme,” Li said.
Although Li and his team were not the first researchers to theorize copper-doped bismuth selenide could contain the Dirac electrons needed for quantum computation, they were the first to actually detect them, thus proving the theory correct.
But students shouldn’t expect to complete their CTools assignments on a quantum computer anytime soon. Lawson said students don’t interact with quantum computers because they don’t yet work as efficiently as classical computers.
Still, many students use classical computers to do complicated calculations, which takes a long time.
“Quantum computers hold the promise of being able to do these computations much faster,” Lawson said. “The technology is not there yet, but there is a lot of potential.”
Lawson said further experiments are necessary to ensure potential topographical superconductors behave in ways the initial research has shown. Further research initiatives will then attempt to find ways to employ their properties in user-friendly quantum computers.
“We are on the ground floor of these materials,” Lawson said. “There is a long road ahead.”