Engineers at the University of New South Wales (UNSW) have made a breakthrough in quantum computing research by creating a new type of quantum bit – qubit, that is able to stay in a stable superposition for 10 times longer than previously achieved, thereby, expanding the time during which calculations could be performed in a future silicon quantum computer.
The quantum logic gate made of silicon, enables calculations between two qubits of information. In simpler terms, a quantum version of computer code can be written and manipulated using two quantum bits in a silicon microchip. The qubit, also known as a “dressed quantum bit” has a record-breaking dephasing time of 2.4 milliseconds, it consists of the spin of a single atom made from silicon that has been combined at its heart with an electromagnetic field.
The beauty of the dressed qubit is that it can retain information for far longer than an “undressed” qubit, meaning that the qubit can hold its delicate superposition long enough to perform complex calculations, as well as enable scientists to manipulate the dressed qubit in ways that wouldn’t be possible with the undressed qubit.
For the first time, calculations between silicon quantum bits has been demonstrated. The quantum code is built upon a class of phenomena known as ‘quantum entanglement,’ which allows for a seemingly counterintuitive phenomena such as the measurement of one particle instantly affecting another— even if they are at the opposite ends of the universe.
The team says the race to build a quantum computer has been called the “space race of the 21st century”, as it is both difficult and ambitious challenge to undertake. To achieve this, the UNSW team constructed a device, known as a quantum logic gate, that allows for calculations to be performed between two quantum bits, or ‘qubits.’ This completes the physical components needed to realize super powerful silicon quantum computers.
Arne Laucht, a research fellow at the School of Electrical Engineering & Telecommunications at UNSW, and lead author of the paper said,
We have created a new quantum bit where the spin of a single electron is merged together with a strong electromagnetic field. This quantum bit is more versatile and more long-lived than the electron alone, and will allow us to build more reliable quantum computers.
The appeal, however, is the potential to deliver revolutionary tools for tackling otherwise impossible calculations, such as the design of complex drugs and advanced materials, or the rapid search of large-scale, unsorted databases.
Following the advancements UNSW has achieved in quantum computing, the federal government has allocated AU$26 million of its AU$500 million science funding to support its work in quantum computing. The science funding forms part of Australia’s AU$1.1 billion National Innovation and Science Agenda that was unveiled in December.
Within 48 hours of cash injection from the federal government, the Commonwealth Bank of Australia pledged AU$10 million over five years to support the university’s researchers. Matching the Commonwealth Bank’s efforts, Telstra also pledged AU$10 million over five years, to boost UNSW’s capacity to develop the world’s first silicon-based quantum computer. According to the university, it is the only research group in the world that can make atomically precise devices in silicon.
