Leti, a technology research institute of CEA Tech, and its research partners have demonstrated a potentially scalable readout technique that could be fast enough for high-fidelity measurements in large arrays of quantum dots.

In a paper presented at IEDM 2019, the international research team reported its work on developing a toolkit on a SOI MOSFET-based prototyping platform that enables fast reading of the states of charge and spin. The study explored two gate-based reflectometry readout systems for probing charge and spin states in linear arrangements of MOS split-gate-defined arrays of quantum dots. The first system gives the exact number of charges entering the array and can help to initialize it. It can also read spin states, albeit in relatively small arrays. The second one gives the spin state in any quantum dot regardless of the array length but is not useful for tracking charge number. Both readout schemes can be used complementarily in large arrays.

The study's findings “bear significance for fast, high-fidelity, single-shot readout of large arrays of foundry-compatible silicon MOS spin qubits,” the paper notes.

“The short-term efforts for our team going forward will be a joint optimization to increase speed and reliability of the readouts,” said CEA-Leti's Louis Hutin, lead author on the paper. “The longer-term goal is to transfer this know-how on a larger scale and to less conventional architectures, featuring an optimized topology for error correction.”

Reflectometry is a technique that leverages signal reflections along a conducting line when an incident RF wave meets an impedance discontinuity. In CEA-Leti's study, the probing line was connected to the MOS gate of a silicon quantum dot. The system was prepared so that the load impedance depends on the spin state of the qubit, which enabled the team to monitor single spin events non-destructively and almost as they occurred.

In addition to CEA-Leti, the research team includes CNRS Institut Néel and CEA-IRIG, Grenoble, France; the Niels Bohr Institute, University of Copenhagen, Denmark; and Hitachi Cambridge Laboratory and Cavendish Laboratory, University of Cambridge, UK. Their paper is titled “Gate Reflectometry for Probing Charge and Spin States in Linear Si MOS Split-Gate Arrays”.

AngelTech Live III: Join us on 12 April 2021!

AngelTech Live III will be broadcast on 12 April 2021, 10am BST, rebroadcast on 14 April (10am CTT) and 16 April (10am PST) and will feature online versions of the market-leading physical events: CS International and PIC International PLUS a brand new Silicon Semiconductor International Track!

Thanks to the great diversity of the semiconductor industry, we are always chasing new markets and developing a range of exciting technologies.

2021 is no different. Over the last few months interest in deep-UV LEDs has rocketed, due to its capability to disinfect and sanitise areas and combat Covid-19. We shall consider a roadmap for this device, along with technologies for boosting its output.

We shall also look at microLEDs, a display with many wonderful attributes, identifying processes for handling the mass transfer of tiny emitters that hold the key to commercialisation of this technology.

We shall also discuss electrification of transportation, underpinned by wide bandgap power electronics and supported by blue lasers that are ideal for processing copper.

Additional areas we will cover include the development of GaN ICs, to improve the reach of power electronics; the great strides that have been made with gallium oxide; and a look at new materials, such as cubic GaN and AlScN.

Having attracted 1500 delegates over the last 2 online summits, the 3rd event promises to be even bigger and better – with 3 interactive sessions over 1 day and will once again prove to be a key event across the semiconductor and photonic integrated circuits calendar.

So make sure you sign up today and discover the latest cutting edge developments across the compound semiconductor and integrated photonics value chain.

REGISTER FOR FREE

VIEW SESSIONS