One of the biggest challenges in quantum computing technology is that quantum bits, qubits, in order to work properly and preserve their quantum state, must be cooled to near absolute zero temperature, a temperature that reigns only in the vast volumes of empty space. However, numerous groups of scientists are searching for technologies to create qubits that will be able to remain in a quantum superposition state at normal ambient temperature. And quite a serious breakthrough in this direction was achieved by the group of Dr. Mohammad Choucair from the University of Sydney, which worked together with their colleagues from Switzerland and Germany.
The most interesting thing about this discovery is the fact that the starting material for the production of “high-temperature” qubits is ordinary naphthalene, a substance used to protect clothing from moths. Scientists noticed that when naphthalene is burned under certain conditions, regular-shaped carbon nanospheres, the closest relatives of fullerenes, can be found in the remaining ash. These nanospheres, like all other unusual forms of carbon, have a number of unique properties, including quantum properties.
Moreover, carbon nanospheres extracted from naphthalene ash are easy enough to integrate into the silicon elements of the processor chip of a future real quantum computer. Experts from the Centre for Quantum Computation and Communication Technology (CQC2T) in Sydney are already working on this computer.
In their experiments, the scientists used carbon nanospheres, with a diameter of 37±7 nanometers. Using brief pulses of an alternating magnetic field, the scientists achieved alignment of the spins of all the electrons of the carbon atoms and observed their further behavior. Experimental data showed that all electrons kept their spin (quantum state) for 175 nanoseconds at an ambient temperature of 300 degrees Kelvin. And that’s already enough time to use this “group” electron spin as a quantum bit.
“With our discovery, we have brought the field of practical quantum computing one step closer,” says Mohammed Chukayr, “However, this step is wide enough that we can expect the first examples of high-temperature quantum computing systems to appear in the next few years.
