Abstract

Local interlayer charge polarization of twisted bilayer hexagonal boron nitride (t2BN) is calculated and parametrized as a function of twist angle and perpendicular electric fields through tight-binding calculations on lattice relaxed geometries. Lattice relaxations tend to increase the bandwidth of the nearly flat bands, where widths smaller than approximately 1 meV are expected for theta <= 1.08 degree for parallel BN/BN alignment and for theta < 1.5 degree for antiparallel BN/NB alignment. Local interlayer charge polarization maxima of approximately 2.6 pC/m corresponding to interlayer electron density differences of approximately 1.3 x 10¹² cm⁻² are expected at the AB and BA stacking sites of BN/BN aligned t2BN in the long moire period limit for theta much less than 1 degree, and evolves non-monotonically with a maximum of approximately 3.5 pC/m at theta = 1.6 degree before reaching approximately 2 pC/m for theta = 6 degree. The electrostatic potential maxima due to the t2BN moire patterns are overall enhanced by approximately 20% with respect to the rigid system assuming potential modulation depths of up to approximately 300 mV near its surface. In BN/BN aligned bilayers the relative areas of the AB or BA local stacking regions can be expanded or reduced through a vertical electric field depending on its sign.

Abstract

Local interlayer charge polarization of twisted bilayer hexagonal boron nitride (t2BN) is calculated and parametrized as a function of twist angle and perpendicular electric fields through tight-binding calculations on lattice relaxed geometries. Lattice relaxations tend to increase the bandwidth of the nearly flat bands, where widths smaller than approximately 1 meV are expected for theta <= 1.08 degree for parallel BN/BN alignment and for theta < 1.5 degree for antiparallel BN/NB alignment. Local interlayer charge polarization maxima of approximately 2.6 pC/m corresponding to interlayer electron density differences of approximately 1.3 x 10¹² cm⁻² are expected at the AB and BA stacking sites of BN/BN aligned t2BN in the long moire period limit for theta much less than 1 degree, and evolves non-monotonically with a maximum of approximately 3.5 pC/m at theta = 1.6 degree before reaching approximately 2 pC/m for theta = 6 degree. The electrostatic potential maxima due to the t2BN moire patterns are overall enhanced by approximately 20% with respect to the rigid system assuming potential modulation depths of up to approximately 300 mV near its surface. In BN/BN aligned bilayers the relative areas of the AB or BA local stacking regions can be expanded or reduced through a vertical electric field depending on its sign.

Abstract

Local interlayer charge polarization of twisted bilayer hexagonal boron nitride (t2BN) is calculated and parametrized as a function of twist angle and perpendicular electric fields through tight-binding calculations on lattice relaxed geometries. Lattice relaxations tend to increase the bandwidth of the nearly flat bands, where widths smaller than approximately 1 meV are expected for theta <= 1.08 degree for parallel BN/BN alignment and for theta < 1.5 degree for antiparallel BN/NB alignment. Local interlayer charge polarization maxima of approximately 2.6 pC/m corresponding to interlayer electron density differences of approximately 1.3 x 10¹² cm⁻² are expected at the AB and BA stacking sites of BN/BN aligned t2BN in the long moire period limit for theta much less than 1 degree, and evolves non-monotonically with a maximum of approximately 3.5 pC/m at theta = 1.6 degree before reaching approximately 2 pC/m for theta = 6 degree. The electrostatic potential maxima due to the t2BN moire patterns are overall enhanced by approximately 20% with respect to the rigid system assuming potential modulation depths of up to approximately 300 mV near its surface. In BN/BN aligned bilayers the relative areas of the AB or BA local stacking regions can be expanded or reduced through a vertical electric field depending on its sign.

Abstract

Local interlayer charge polarization of twisted bilayer hexagonal boron nitride (t2BN) is calculated and parametrized as a function of twist angle and perpendicular electric fields through tight-binding calculations on lattice relaxed geometries. Lattice relaxations tend to increase the bandwidth of the nearly flat bands, where widths smaller than approximately 1 meV are expected for theta <= 1.08 degree for parallel BN/BN alignment and for theta < 1.5 degree for antiparallel BN/NB alignment. Local interlayer charge polarization maxima of approximately 2.6 pC/m corresponding to interlayer electron density differences of approximately 1.3 x 10¹² cm⁻² are expected at the AB and BA stacking sites of BN/BN aligned t2BN in the long moire period limit for theta much less than 1 degree, and evolves non-monotonically with a maximum of approximately 3.5 pC/m at theta = 1.6 degree before reaching approximately 2 pC/m for theta = 6 degree. The electrostatic potential maxima due to the t2BN moire patterns are overall enhanced by approximately 20% with respect to the rigid system assuming potential modulation depths of up to approximately 300 mV near its surface. In BN/BN aligned bilayers the relative areas of the AB or BA local stacking regions can be expanded or reduced through a vertical electric field depending on its sign.