Twist-controlled modulation of quantum emitters in hexagonal boron nitride.

Stacking and twisting two-dimensional materials have garnered enormous attention across the condensed matter and nanophotonic communities. The surge of interest is driven by emergence of photophysical phenomena from interlayer coupling. Here, we demonstrate that the twist df can modulate quantum emitters at room temperature. We use a van der Waals (vdW) stack of hexagonal boron nitride (hBN) and model the emission properties of quantum emitters as a function of the twist angle. Density functional theory results show that the embedded emitters are strongly influenced by the twist angle and the stacking of the top hBN layer. We consequently engineer these systems experimentally and demonstrate in situ tuning of embedded quantum emitters by mechanically twisting the top hBN layer, achieving tunability of over 30 nanometers (~100 milli-electron volts). Our work demonstrates that mechanical twisting can be harnessed to modulate quantum emitters in a vdW material, marking a crucial step toward a programmable on-chip quantum circuitry.