Emergent Inductance from Spin Fluctuations in Strongly Correlated Magnets

Recently, the intriguing phenomenon of emergent inductance has been theoretically proposed and experimentally observed in nanoscale spiral spin systems subjected to oscillating currents. Building upon these recent developments, we put forward the concept of emergent inductance in strongly correlated magnets in the normal state with spin fluctuations. It is argued that the inductance shows a positive peak at temperatures above the ordering temperature. As for the frequency dependence, in systems featuring a single-band structure or a gapped multiband, we observe a Drude-type inductance, while in gapless multiband systems, a non-Drude inductance with a sharp dip near zero frequency. These results offer valuable insights into the behavior of strongly correlated magnets and open up new possibilities for harnessing emergent inductance in practical applications.

Figure 1

Our main findings of emergent inductance in strongly correlated magnets at high temperatures. (a) The schematics of inductance in temperatures (upper panel) and in frequencies (lower panel). (b) The classification of inductance: Drude and non-Drude types.

Figure 2

The order parameters (upper panel) and log-scale inductance (lower panel) in temperatures from the self-consistent SFMFT with $\tilde{J}=1$ on (a) 1D spin chain, (b) 2D honeycomb lattice, and (c) 2D kagome lattice. $T$ is in units of $\tilde{J}$, and $L$ is in units of $\sim 0.1\mathrm{\mu }\mathrm{H}$ for the 100 nm cubic sample. The blue lines are the coherent spinon propagation $\chi$, the orange lines are the Lagrange multiplier $\lambda$, the black lines are the maximum of inductance $L$ in $\omega \in [-3,3]$, and the dotted lines denote $T_{\chi }$.

Figure 3

The energy band (upper panel) and inductance in frequencies (lower panel) near $T_{\chi }$, for (a) the 1D spin chain, (b) 2D honeycomb lattice, and (c) 2D kagome lattice. $E(k)$ and $\omega$ are in units of $\tilde{J}$, and $L$ has the same unit as above. The 1D spin chain is a single-band system, exhibiting Drude-type inductance. The honeycomb and kagome lattices are gapless multiband systems, exhibiting a sharp negative dip structure near $\omega =0$.