Single-shot Readout of an Electron Spin in Silicon

Taking aim at silicon Silicon transistors in microelectronics are shrinking to close to the size at which quantum effects begin to have an impact on device performance. As silicon looks certain to remain the semiconductor material of choice for a while yet, such effects may be turned into an advantage by designing silicon devices that can process quantum information. One approach is to make use of electron spins generated by phosphorus dopant atoms buried in silicon, as they are known to represent well-isolated quantum bits (qubits) with long coherence times. It has not been possible to control single electrons in silicon with the precision for qubits, but now Andrea Morello and colleagues report single-shot, time-resolved readout of electron spins in silicon. This is achieved by placing the phosphorus donor atoms near a charge-sensing device called a single-electron transistor, which is fully compatible with current microelectronic technology. The demonstrated high-fidelity single-shot spin readout opens a path to the development of a new generation of quantum computing and spintronic devices in silicon.