Vibrational Squeezing via Spin Inversion Pulses

TL;DR

This paper investigates the effects of radio-frequency pulses in Magnetic Resonance Force Microscopy, revealing how they can cause parametric amplification of vibrations, and proposes methods to cancel or utilize this effect for improved measurements.

Contribution

It identifies the parametric amplification caused by RF pulses in MRFM and offers strategies for its cancellation or potential use to enhance measurement sensitivity.

Findings

Parametric amplification can occur due to RF pulses in MRFM.

Auxiliary RF pulses or calibration can cancel the amplification.

Future applications may leverage amplification to reduce noise.

Abstract

Magnetic Resonance Force Microscopy (MRFM) describes a range of approaches to detect nuclear spins with mechanical sensors. MRFM has the potential to enable magnetic resonance imaging (MRI) with near-atomic spatial resolution, opening up exciting possibilities in solid state and biological research. In many cases, the spin-mechanics coupling in MRFM is engineered with the help of periodic radio-frequency pulses. In this paper, we report that such pulses can result in unwanted parametric amplification of the mechanical vibrations, causing misinterpretation of the measured signal. We show how the parametric effect can be cancelled by auxiliary radio-frequency pulses or by appropriate post-correction after careful calibration. Future MRFM measurements may even make use of the parametric amplification to reduce the impact of amplifier noise