Electrically controlled nuclear polarization of individual atoms

Area of Science:

• Condensed matter physics
• Quantum information science
• Surface science

Background:

• Nuclear spins are sensitive probes in chemistry and materials science, crucial for quantum information processing.
• Nuclear Magnetic Resonance (NMR) probes local magnetic environments, but single-atom sensitivity requires overcoming low thermal polarization.
• Hyperpolarization, achieved via hyperfine coupling with electron spins, enhances nuclear spin polarization for advanced applications.

Purpose of the Study:

• To achieve single-atom scale NMR sensitivity.
• To demonstrate a method for polarizing nuclear spins of individual atoms.
• To utilize nuclear spin polarization for probing local magnetic environments.

Main Methods:

• Utilizing a spin-polarized current in a scanning tunneling microscope to polarize nuclear spins of individual copper atoms.
• Employing the electron-nuclear flip-flop hyperfine interaction for angular momentum transfer.
• Controlling nuclear polarization via current direction and amplitude.

Main Results:

• Successfully polarized nuclear spins of individual copper atoms on a surface.
• Enabled the detection of NMR signals from individual copper atoms.
• Demonstrated sensing of the local magnetic environment of individual copper electron spins.

Conclusions:

• Single-atom NMR is achievable through current-driven nuclear spin hyperpolarization.
• This technique allows for sensitive probing of magnetic properties at the atomic scale.
• The method holds promise for advancements in quantum information processing and materials science.