Intel’s two main research institutions Intel Labs (Intel Labs) and the Institute for Basic Materials Research (Components Research) recently announced that they have made significant progress in the large-scale production of quantum computing processors.
At the 2022 Silicon Quantum Electronics Symposium in Orford, Quebec, Intel researchers said that Intel’s Transistor R&D Center has been able to demonstrate the highest levels of yield and uniformity when manufacturing “silicon spin quantum bit devices,” which is considered an important milestone for Intel as it moves toward being able to manufacture quantum computing chips on existing transistor manufacturing processes.
Intel is one of the key players in the race to build quantum computers. A quantum computer is a more advanced machine that can encode data as “quantum bits” instead of the bits used in traditional computers. The advantage of a quantum bit is that it is not limited to the state 1 or 0, but can exist as two states at the same time, a property known as superposition.
This is mainly due to the singularity of quantum physics. Intel compares a quantum bit to a coin, which can be heads, tails, or a constantly rotating state. When the coin is spinning, it can be considered both heads and tails at the same time.
Intel further explains that if a spinning coin can represent two states at once, then two spinning coins can represent four states: HH, TT, HT, and TH. Thus, the possibilities expand rapidly, and three spinning coins can represent eight states.
It is important that you understand that the ability of quantum bits to represent multiple states makes them more powerful than traditional bits, so the more quantum bits in a quantum computer, the more capable the machine becomes.
Surprisingly, although quantum bits look amazing, they are actually manufactured in the same way as traditional computer chips, as “spin quantum bits” on silicon wafers, with the major difference being that they are a bit more fragile and can only exist in very low temperatures to maintain their stability.
So far, most research processes have focused on creating one quantum chip at a time, while Intel’s approach is different, using existing extreme ultraviolet lithography to create a typical 300 mm wafer, which contains multiple quantum chips. According to Intel, this prototype demonstrates the strongest consistency to date, with a yield of about 95 percent.
Figure: Image of an Intel cryogenic detector ingested during automation, showing a 1.6 Kelvin quantum bit device in which quantum dots can be formed at all 16 positions (4 sensors and 12 quantum bit positions) and tuned to the last individual electron without input manipulation by an engineer. These results are achieved with the uniformity and repeatability of the Intel-built device, and they are collected on an entire wafer. The system runs continuously to generate the largest dataset of quantum dot devices known to date.
James Clarke, Intel’s director of quantum hardware, said the research shows that the idea of using Intel’s existing transistor process nodes to make quantum chips is a “sound strategy” that will see results as the technology matures.
Because Intel has achieved higher yields and consistency compared to earlier chips, Intel can now use statistical process control techniques to determine which areas of the manufacturing process can be optimized. In this way, Intel can accelerate its research efforts and expects to mass produce thousands or even millions of quantum bits for commercial quantum computers within a day.
Clarke said, “Going forward, we will continue to improve the quality of these devices and develop larger scale systems that use these steps as building blocks to help us move forward quickly.”
