Archer achieves milestone in quantum transistor control & readout

Archer has reported achieving a key technical milestone in its development of quantum devices. The company announced it has successfully demonstrated electrical control of its quantum single electron transistor devices, crucial for accurately reading quantum information.

This step brings Archer closer to its goal of achieving a working single qubit based on carbon material technology.

Electrical control

The company's latest results show that it can use electrical signals to control and measure quantum properties within its devices. These measurements, known as readouts, are fundamental for accessing quantum information, which is essential for quantum computing applications. Archer said that achieving effective readout and control is required for moving towards demonstration of a single qubit, which forms the foundation of a quantum computing system.

"Achieving readout and control is key for our qubit demonstration, and the qubit is the foundation in building a full quantum chip. Showing electrical gating within our quantum single SET devices, helps us improve readout capabilities," said Dr Simon Ruffell, CEO, Archer.

Manufacturing integration

Archer is developing its quantum devices using carbon nano onions and carbon films. The company says that these carbon films are designed to be produced using standard semiconductor fabrication techniques, allowing for potential future integration with conventional chip-making processes. This compatibility is seen as an important factor in moving towards scalable production of quantum devices for commercial applications.

In its recent series of tests, Archer examined large numbers of its single electron transistor devices under various temperature conditions. According to the company, this approach allowed it to gather detailed insight into the behaviour of its devices, confirm reproducibility, and build a comprehensive understanding of their quantum properties. These elements are vital for reliable scaled manufacturing and engineering of such technology.

Readout methods

Archer noted that its pathway to achieving reliable qubit readout includes multiple approaches. Alongside the electronically controlled single electron transistor devices, the company has previously demonstrated the feasibility of using electrically detected magnetic resonance as a method of reading quantum states. Having more than one method is intended to reduce technological risk as the company advances towards a full demonstration of a single working qubit.

Readout of a qubit depends on controlling the spin states of single electrons, typically managed through precise microwave pulses. The resulting spin state must then be detected immediately after control, a process that Archer is developing with both its current device technologies.

Next milestones

The next phase in the company's research focuses on demonstrating the ability to read out electron spin states while operating its devices in magnetic fields. According to Archer, initial testing in these conditions is already underway, with early qubit readout results expected next month.

Ruffell explained how the recent results also have broader significance for device engineering and manufacturability. "We're developing the qubit technology on carbon nano onions and films. Although this work was done on our nano onions, it derisks the film material technology. By using carbon film materials, we can bolster the manufacturability our quantum technology, as films allow for better integration with conventional chip making processes," said Ruffell.