Anisotropic electron-nuclear interactions in a rotating quantum spin bath

TL;DR

This paper investigates how rapid physical rotation affects electron-nuclear interactions in diamond NV centers, revealing rotationally dependent decoherence mechanisms that impact quantum control in systems with motional degrees of freedom.

Contribution

It demonstrates that high-speed rotation introduces non-averaged anisotropic hyperfine interactions, providing new insights into quantum control in rotating quantum systems.

Findings

Rotation at up to 300,000 rpm causes decoherence via frequency modulation.

Off-axis magnetic fields lead to rotational dependence of hyperfine interactions.

Certain anisotropic interactions cannot be averaged out at achievable rotation speeds.

Abstract

The interaction between a central qubit spin and a surrounding bath of spins is critical to spin-based solid state quantum sensing and quantum information processing. Spin-bath interactions are typically strongly anisotropic, and rapid physical rotation has long been used in solid-state nuclear magnetic resonance to simulate motional averaging of anisotropic interactions, such as dipolar coupling between nuclear spins. Here, we show that the interaction between electron spins of nitrogen-vacancy centers and a bath of $^{13}$C nuclear spins in a diamond rotated at up to 300,000rpm introduces decoherence into the system via frequency-modulation of the nuclear spin Larmor precession. The presence of an off-axis magnetic field necessary for averaging of the dipolar coupling leads to a rotational dependence of the electron-nuclear hyperfine interaction, which cannot be averaged out with experimentally achievable rotation speeds. Our findings offer new insights into the use of physical rotation for quantum control with implications for quantum systems having motional and rotational degrees of freedom that are not fixed.