Arne Laucht and A. Morello, University of New South Wales (UNSW), Sydney, Australia, and colleagues have generated quantum bits (qubits) that persist ten times longer than common variants. They have achieved this by incorporating the quantum bit atoms into a strong, rapidly oscillating microwave field. This makes the qubits much less sensitive to interfering influences. For this approach, the team used a phosphor atom embedded in silicon.
The biggest hurdle in using quantum objects as computers is to maintain their coherence long enough to perform useful computing operations. The qubit embedded in the microwave field reacts less sensitively to external disturbances. This is because the field, which is oscillating in high frequency, shields it from interference in other frequency ranges. This makes it possible to hold two such quantum bits in a state of coherence for a longer time.
In the experiment, the scientists achieved a coherence time of at least 2.4 ms. This quantum bit could make it possible to build more reliable quantum computers, the researchers say.
- A dressed spin qubit in silicon,
Arne Laucht, Rachpon Kalra, Stephanie Simmons, Juan P. Dehollain, Juha T. Muhonen, Fahd A. Mohiyaddin, Solomon Freer, Fay E. Hudson, Kohei M. Itoh, David N. Jamieson, Jeffrey C. McCallum, Andrew S. Dzurak, A. Morello,
Nat. Nanotechnol. 2016.