arXiv subjects

Alistair Inglis

Publications and source records attributed to Alistair Inglis.

4 recordsLinked to original sources

arXiv2025

Room temperature optical control of spin states in organic diradicals

We report a family of luminescent alternant diradicals which, at room temperature, support a ground-state spin-triplet, near-unity photoluminescence quantum yields, and optical spin addressability. These diradicals comprise trityl groups meta-linked via pyridyl or phenyl groups, enabling optically bright triplet-to-triplet and singlet-to-singlet transitions. At room temperature, we observe optically detected magnetic resonance in these systems at zero magnetic field and a strong magneto-photoluminescence (10% modulation at 2 mT applied magnetic field). Distinct photoluminescence bands (at 630 nm and 700 nm) show opposite-sign spin-optical responses, arising from spin-selective intersystem crossing between triplet and singlet manifolds. These bright, all-organic diradicals offer a new set of chemically tunable materials for room temperature spin-optical interfaces, paving the way for application as quantum sensors.

cond-mat.mtrl-sci↗

arXiv2019

Onset of spin wave time-domain fractals in a dynamic artificial crystal

We report on the first observation of an exact fractal pattern in the time-domain arising spontaneously from a dynamic artificial crystal (DAC). The all-magnon process occurs in a passive, unlithographed magnetic waveguide. The DAC was created by a standing spin wave of frequency $f_{\mathrm{DAC}}$ in a region of nonlinear waveguide, resulting in a spatio-temporally periodic potential. The interaction of travelling spin waves of frequency $f'$ with the DAC resulted in a series of new modes appearing in a comb with intervals $Δf^{(0)} = \mid f_{\mathrm{DAC}}-f'\mid$. As $H$ was increased a 1st pre-fractal pattern was observed with frequency interval $Δf^{(1)} =Δf^{(0)}/2$. Finally, the onset of a 2nd pre-fractal was observed with frequency interval $Δf^{(2)} =Δf^{(1)}/2 = Δf^{(0)}/4$. The magnetic field dependence of the nonlinear signals effect matched that of the DAC. The fractal-like behavior was demonstrated for different values of $f'$.

cond-mat.mes-hall↗

arXiv2019

Indirect observation of phase conjugate magnons from non-degenerate four-wave mixing

A phase conjugate mirror utilising four-wave mixing in a magnetic system is experimentally realised for the first time. Indirect evidence of continuous-wave phase conjugation has been observed experimentally and is supported by simulations. The experiment utilizes a pump-probe method to excite a four-wave mixing process. Two antennae are used to pump a region of a thin-film yttrium iron garnet waveguide with magnons of frequency $f_{1}$ to create a spatio-temporally periodic potential. As the probe magnons of $f_{\mathrm{p}}$ impinge on the pumped region, a signal with frequency $f_{\mathrm{c}} = 2f_{1}-f_{\mathrm{p}}$ is observed. The amplitude of the nonlinear signal was highly dependent on the applied magnetic field $H$. Width modes of the probe magnons and standing wave modes of the pump magnons were shown to affect the amplitude of the signal at $f_{\mathrm{c}}$. Experimental data is compared with simulations and theory to suggest that $f_{\mathrm{c}}$ is a phase conjugate of $f_{\mathrm{p}}$.

cond-mat.mes-hall↗

arXiv2018

A Microscopic Explanation of Microwave Spin Pumping

We contend that Microwave Spin Pumping was first predicted and observed - albeit using a different and more sensitive detection mechanism than Inverse Spin Hall Effect - in the 1950's. This discovery was the founding step in the widely used analytical tool that is now known as Dynamic Nuclear Polarisation. Recognising this hitherto unsung connection between 20th Century Magnetic Resonance and 21st Century Spintronics not only helps to explain and unify contemporary metallic spin pumping observations: it is also the key to unlocking the immense and very sophisticated toolbox of Magnetic Resonance and placing it at the disposal of the future of Spintronics.

cond-mat.mes-hall↗