High Harmonic Generation Driven by Counter-Rotating Bicircular Laser Fields from Polar Chemical Bonds in <i>h</i>-BN

High harmonic generation (HHG) driven by counter-rotating bicircular (CRB) pulses excitation has been observed from several solid targets, where circularly polarized harmonics are emitted. We study this process using time-dependent density functional theory (TDDFT) to calculate the crystal orientation dependence of the circularly polarized high harmonics from a monolayer h-BN. The resulted can be interpreted by the real space electron dynamics of electrons in polar chemical bonds. The yield of circularly polarized high harmonics (CHHs) can be optimized by controlling the direction of valence electron dynamics. Our findings pave the way for exploring the binding potential from spectrum and all-optically processing information