Fully integrated quantum processor created

Equal1 Laboratories, a silicon-based quantum computing company, has demonstrated a fully integrated quantum processor unit (QPU) operating at 3.7 kelvin ― a major milestone with implications for the trajectory of quantum computing.

The company is addressing a major challenge for the quantum computing industry of scaling the number of qubits so that a quantum computer can tackle useful, real-world problems. With its QPU, Equal1 has developed a disruptive, scalable and cost-effective quantum computing technology, based on a commercially available silicon semiconductor process.

The QPU employs patented, Equal1-designed, nanometre-scale quantum dots to create qubits (the quantum equivalent to digital bits) on a standard silicon CMOS process. In addition to the silicon qubits, all control and read-out electronics required for a fully functioning QPU are integrated on-chip with over 10 million transistors. Due to the operation of the qubits at 3.7 K (referred to as ‘hot qubits’) and the level of integration the team has achieved, the form factor of the quantum demonstrator is far smaller than alternative technologies (rack-sized versus room-sized).

The QPU was manufactured on GlobalFoundries’ ultralow-power 22FDX platform, requiring no special process extensions for quantum operation, which played a key role in enabling Equal1 to achieve its results. Equal1 also designed and manufactured the closed cryogenic and vacuum system, together with the control and communication electronics to maintain the chip at 3.7 K and interface to room temperature. The team designed the complex mixed signal circuits, such as high-speed pulse generator, ADCs, DACs and cryogenic memory, using EDA software from Cadence Design Systems, in particular the Spectre Simulation Platform’s new support for ultralow-temperature models which are key to cryoelectronic design validation.

Two Equal1 quantum demonstrator machines have each been running for over 24 cumulative months with no unplanned downtime, and Rabi oscillations have been observed in three-dot arrays with a coherence time of 150 ns. Due to the integrated nature of the technology, the electronic pulses that control the qubits are generated on-chip and therefore are extremely fast, enabling a short enough pulse time for the QPU to demonstrate quantum behaviour. The team has proven the repeatability of the results and consistency with quantum modelling and simulations.

“By taking advantage of shrinking transistor geometries, we have demonstrated that integration into the millions of qubit range is possible, with moderate cooling requirements compared to other qubit technologies,” said Equal1 CEO Dirk Leipold. “Our quantum computing technology delivers affordable AI solutions to our customers at a much lower carbon footprint.”

“Our team’s ability to demonstrate quantum behaviour on a fully integrated QPU will enable us to soon solve challenges in AI that cannot be solved today,” added Equal1 CTO Elena Blokhina. “We are proud of the milestone accomplishment and are excited to scale our technology to the next level.”

Image: Quantum dot array from the Equal1 QPU.

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