Atomically engineered electron spin lifetimes of 30 s in silicon

Area of Science:

• Quantum computing
• Condensed matter physics
• Nanotechnology

Background:

• Scaling quantum computers requires high-fidelity readout of individual spin qubits.
• Electron spin lifetime is a critical limitation for multi-qubit readout fidelity.

Purpose of the Study:

• To achieve record-long electron spin lifetimes in a nanoelectronic device.
• To demonstrate high-fidelity sequential readout of multiple spin qubits.

Main Methods:

• Atomic-level engineering of electron wave functions in phosphorus atom quantum dots.
• Minimizing spin relaxation through precise control of qubit environment.

Main Results:

• Demonstrated electron spin lifetimes up to 30 seconds, the longest reported for any electron spin qubit in a nanoelectronic device.
• Achieved sequential readout fidelities as high as 99.8% for two electron spin qubits, exceeding the fault-tolerant threshold for surface codes.

Conclusions:

• Atomic-level engineering significantly enhances electron spin qubit lifetimes by minimizing spin relaxation.
• The demonstrated long lifetimes and high fidelities are crucial for advancing multiqubit systems based on donors in silicon for quantum computation.