In-situ Overhauser-enhanced nuclear magnetic resonance at less than 1 μ T using an atomic magnetometer

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>The development of atomic magnetometers has led to nuclear magnetic resonance (NMR) in zero and ultralow magnetic fields without using cryogenic sensors. However, <I>in-situ</I> detection, meaning that a sample locates in the detection space beside a vapor cell, has been conducted only with parahydrogen-induced polarization. Other hyperpolarization techniques remain unexplored yet. In this work, we demonstrate that Overhauser dynamic nuclear polarization allows <I>in-situ</I> NMR detection with an atomic magnetometer at less than 1 μ T. The <SUP> 1 </SUP> H NMR signal of a nitroxide radical solution was observed at 13.83 Hz, which corresponds to 325 nT. Signal-to-noise ratio was 32 after sixteen averages. On the Larmor precession of <SUP> 1 </SUP> H spins, a decaying oscillation was superimposed. We attribute it to a transient <SUP> 87 </SUP> Rb spin precession in response to a non-adiabatic field variation. This work shows a new capability of zero- and ultralow-field NMR.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The first <I>in-situ</I> Overhauser-enhanced nuclear magnetic resonance experiment using an atomic magnetometer at ultra-low field. </LI> <LI> Signal-to-noise ratio was 32 after sixteen averages. </LI> <LI> On the Larmor precession of <SUP> 1 </SUP> H spins, a decaying oscillation was superimposed. </LI> <LI> We attribute it to a transient <SUP> 87 </SUP> Rb spin precession in response to a non-adiabatic field variation. </LI> <LI> Atomic magnetometry technique shows a new capability of zero and ultralow-field NMR. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>