Intel: Silicon spin qubits hold promise for quantum computing

Technology News | February 19, 2018

By Rich Pell

The company says that it has invented a spin qubit fabrication flow on its 300-mm process technology using isotopically pure wafers sourced specifically for the production of spin-qubit test chips. In addition, says Intel, its quantum research partner – Netherlands-based QuTech – has successfully creating a two-qubit spin-based quantum computer that can be programmed to perform two simple quantum algorithms.

Resembling today’s semiconductor electronics and transistors, spin qubits deliver their quantum power by leveraging the spin of a single electron on a silicon device and controlling the movement with tiny, microwave pulses. When the electron spins up, the data signifies the binary value “one”; when it spins down, the data signifies the binary value “zero.”

But, as with superconducting qubits, these electrons can also exist in a “superposition” – i.e., they have the probability of a spin that’s up and down at the same time. In doing so, they can theoretically process tremendous sets of data in parallel – much faster than a classical computer.

Intel says that its investment into spin qubits research is equal to that of its ongoing major research into superconducting qubits, as “it’s not clear yet what form quantum processors – or qubits – will take.” According to the company, spin qubits offer several advantages over their superconducting counterparts:

Spin qubits are much smaller in physical size and their coherence time is expected to be longer – an advantage as researchers aim to scale the system to the millions of qubits that will be required for a commercial system.
Silicon spin qubits can operate at higher temperatures than superconducting qubits (1 kelvin as opposed to 20 millikelvin). This could drastically reduce the complexity of the system required to operate the chips by allowing the integration of control electronics much closer to the processor.
The design of the spin qubit processors highly resembles the traditional silicon transistor technologies. While there are key scientific and engineering challenges remaining to scale this technology, Intel has the equipment and infrastructure from decades of fabricating transistors at scale.

The company says that it is now testing the initial isotopically pure wafers, which were fabricated in the same facility as its advanced transistor technologies. Within a couple of months, it expects to be producing many wafers per week, each with thousands of small qubit arrays.

So far, Intel and QuTech are exploring higher temperature operation of spin qubits with “interesting results” up to 1K – or 50x warmer – than superconducting qubits. Going forward, says Intel, they will continue research on both superconducting and spin qubits across the entire quantum system – or “stack” – from qubit devices to the hardware and software architecture required to control these devices, as well as quantum applications.

For more, see “A programmable two-qubit quantum processor in silicon.”

Intel
QuTech