Semiconductor Bloch-equations formalism: Derivation and application to high-harmonic generation from Dirac fermions

Jan Wilhelm, Patrick Groessing, Adrian Seith, Jack Crewse, Maximilian Nitsch, Leonhard Weigl, Christoph P. Schmid, Ferdinand Evers
We rederive the semiconductor Bloch equations emphasizing the close link to the Berry connection. Our rigorous derivation reveals the existence of two further contributions to the current, in addition to the frequently considered intraband and polarization-related interband terms. The extra contributions become sizable in situations with strong dephasing or when the dipole-matrix elements are strongly wave-number dependent. We apply the formalism to high-harmonic generation for a Dirac metal.
more » ... or a Dirac metal. The extra terms add to the frequency-dependent emission intensity (high-harmonic spectrum) significantly at certain frequencies changing the total signal up to a factor of 10.
doi:10.5283/epub.45685 fatcat:ihqstyq22vh27czwgeqzb34zuy