Deep-Subwavelength Thermal Switch via Resonant Coupling in Monolayer Hexagonal Boron Nitride

Unlike the electrical conductance that can be widely modulated within same material even in deep nanoscale devices, tuning thermal a single system or nanostructure is extremely challenging and requires large-scale device. This prohibits realization of robust ON/OFF states switching flow currents. Here, we present theory switch based on resonant coupling three photonic resonators, analogy to field-effect electronic transistor composed source, gate, drain. As platform, capitalize extreme tunability low-loss resonances observed dielectric function monolayer hexagonal boron nitride (hBN) under controlled strain. We derive hBN from first principles, including phonon-polariton linewidths computed by considering phonon isotope anharmonic phonon-phonon scattering. Subsequently, propose strain-controlled hBN-based modulates more than an order magnitude, corresponding contrast ratio 98%, subwavelength nanostructure.