Annual-modulation fingerprint of the axion wind induced sideband triplet in quantum dot spin qubit sensors

TL;DR

This paper introduces a quantum-dot spin qubit magnetometer capable of detecting axion-like particles through annual and sidereal modulation signals, achieving sensitivities comparable to astrophysical bounds in a laboratory setting.

Contribution

It presents a novel phase-coherent, narrowband magnetometry method using silicon quantum-dot spin qubits to search for axion-electron couplings with enhanced modulation analysis.

Findings

Detected sidereal modulation of the axion signal due to Earth's rotation.

Identified annual amplitude envelope creating sidebands at fixed frequency spacing.

Achieved sensitivity to axion-electron coupling strengths from 10^{-14} to 10^{-10}.

Abstract

We propose a phase-coherent, narrowband magnetometer for searching couplings between axions or axion-like particles (ALPs) and electron spins, using gate-defined silicon quantum-dot spin qubits. With repeated Ramsey echo sequences and dispersive readout, the qubit precession response can be tracked with sub-Hz spectral resolution. The accessible axion mass window is determined using a series of filtering protocols that take into account sensing noise, including readout errors and $1/f$ noise. We demonstrate clear evidence of sidereal modulation of the signal due to Earth's rotation, while Earth's orbital motion produces an annual amplitude envelope that generates sidebands at fixed frequency spacing $\pm \Omega_\oplus$ around the sidereal component. For axion masses between $1$-$10~\mu{\rm eV}$, the proposed method covers axion-electron coupling strengths $g_{ae}$ ranging from $10^{-14}$ to $10^{-10}$. Including both daily and annual modulation patterns in the likelihood analysis enhances the rejection of stationary or instrumental noise. Our results indicate that spin-qubit magnetometry can achieve sensitivities approaching those suggested by astrophysical considerations, providing a complementary, laboratory-based probe of axion-electron interactions. Although we focus on silicon spin-qubit architectures, the approach is broadly applicable to spin-based quantum sensors.