A research team led by Hitachi Cambridge Laboratory has developed a highly-sensitive readout detector for Si-CMOS based quantum computer.
Hitachi Europe Ltd. has announced that researchers at the Hitachi Cambridge Laboratory, working in collaboration with academic partners at the University of Cambridge, University College London, UK, and CEA-LETI, France, have successfully demonstrated a highly-sensitive detector to readout information from a Si-CMOS based quantum computer.
The new detector, which has a charge sensitivity of 1.3 µe/√Hz, is five times more sensitive than the silicon radio-frequency single-electron transistor which has been – according to research – the most sensitive technology for silicon-based quantum computers up to now. The successful demonstration of the new detector represents another step forward towards the realisation of a Si-CMOS based spin quantum computer.
Why do we need quantum computers?
Quantum computers promise to solve some of the most challenging computational problems such as:
- Simulation for revolutionary new materials
- Chemicals and
Research on quantum computation has demonstrated that it is now possible to build small quantum processors in a variety of hardware platforms, and their computational capabilities are approaching those of the most powerful supercomputers. However, to tackle the most demanding computational simulations, quantum computers will need a much larger number of qubits than what current technologies can provide.
Currently, qubits are wired one by one in a very similar way to what was done for the first electronic computers built with discrete components, however, this approach will become unsustainable as quantum processors become increasingly complex.
To solve this challenge, the team is developing Si-CMOS based qubits and integrating them with digital electronics so that in the future, complex quantum processors can be managed with a small number of input/output lines.
Developing Si-CMOS based qubits
Silicon, the base material of large-scale integration technology, is amongst the most promising candidates for large-scale quantum computing as qubits based on the spin of a single electron can retain quantum information for much longer than any other solid-state implementation.
The team have focused on improving the readout circuitry of the Si-CMOS based quantum computer. They have designed a detector that combines Si-CMOS technology and superconducting high-frequency components to detect single-electrons moving in the quantum device. The results revealed an improvement in the sensitivity of a factor of 30 over previous designs, making it five times more sensitive than the best reported readout detector for silicon-based quantum computers.
This research was carried out at Hitachi Cambridge Laboratory in collaboration with academic partners at the University of Cambridge, University College London, UK and CEA-LETI, France, and was supported by funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 688539: MOS-Quito project.
The results have just been published in the 19th July 2018 issue of Physical Review Applied.