Microsoft’s pursuit of a working, scalable quantum computer has hit a breakthrough, according to researchers.
Current working quantum computers of competitors include a small number of qubits (the current record of qubits is held at 200) and Microsoft, unlike IBM, Honeywell and Google, has researched more in-depth into topological qubits in the hope of improving scalability.
The possibility of scaling quantum computing has been an enormous task for researchers to develop due to the highly receptive nature of qubits and the fact they’re sensitive to any and all hardware faults. These faults cause decoherence of quantum entanglement and are quite the barrier for scaling up a quantum computer – it’s thought that you’d need a few thousand qubits for a general-purpose quantum computer to ensure long-term stability.
The current theory goes that topological qubits are more stable than traditional ones, such as those created by trapped ion technologies – and this stability is caused by symmetries in the supporting material. Microsoft is experimenting with superconducting wires of a variety of materials since it’s thought that devices with these qubits implemented will be more fault-tolerant. compact and users will see a reduction in loss of performance. Until now, no one had been able to bring these qubits into the real world.
However, it appears Microsoft has been able to crack open the required underlying physics.
According to a blog post, a team led by Dr Chetan Nayak at Microsoft, the researchers have demonstrated that the groundwork of physics behind topological qubits are sound and that they’ve observed a ‘topological gap’ large enough to prove their point.
What is a topological gap?
It is a measurement of the stability of a qubit while it is in its topological state and capable of being used for computation. While this sounds simple enough, it’s hard to identify the qubits that are in their topological state (using standard probes) so it’s a major breakthrough for Microsoft to have been able to achieve this identification with superconducting wires, and applying models that simulate common faults in the superconducting materials used to create the qubits.
The blog also says:
“Our team has measured topological gaps exceeding 30 μeV,”
“This is more than triple the noise level in the experiment and larger than the temperature by a similar factor. This shows that it is a robust feature. This is both a landmark scientific advance and a crucial step on the journey to topological quantum computation.”
Despite this being a simulated result, and no topological qubit has been produced, the researchers insist that the results remain valid and have been verified by independent consultants.
Phase one, the theoretical underpinnings of topological qubits, has been demonstrated so it’s time for researchers to move onto the next phase – creating them in the lab to verify thet do indeed have the stability and speed advantages that the maths predict.
the post concludes:
“We believe ultimately it will power a fully scalable quantum machine in the future, which will, in turn, enable us to realise the full promise of quantum to solve the most complex and pressing challenges our society faces,”