Quantum Computing Hardware
What is the main reason silicon spin qubits are expected to suit large-scale systems?
- AThey work at room temperature, so no refrigerator is needed at all
- BTheir qubits are photons, so they can be sent far away directly over optical fibers
- CEach qubit is small, about tens to 100 nm, and many of them might be integrated by drawing on CMOS fabrication technology and 300 mm wafer equipment
Show answer and explanation
Answer: C. Each qubit is small, about tens to 100 nm, and many of them might be integrated by drawing on CMOS fabrication technology and 300 mm wafer equipment
A silicon spin qubit confines single electrons in quantum dots formed in silicon by the voltages on gate electrodes and uses the direction of each electron's spin as a qubit. Each qubit is about tens to 100 nm in size, far smaller than a superconducting qubit of about several hundred µm, and the fine patterning of semiconductor fabs, manufacturing on 300 mm wafers and wafer-scale characterization are expected to be applicable. Operation at relatively high temperatures of around 1 K has also been reported, which may make it easier to place control circuits nearby. On the other hand, variation between quantum dots and wiring to many densely packed qubits are challenges.
- A. Qubit operation generally requires cryogenic temperatures of around 1 K or below.
- B. Using photons as qubits is the photonic approach.
- C. Correct. They are expected to be integrated by drawing on semiconductor fabrication technology.