Manifestations of electron interactions in photogalvanic effect in chiral nanotubes

Abstract

Carbon nanotubes provide one of the most accessible experimental realizations of one dimensional electron systems. In the experimentally relevant regime of low doping the Luttinger liquid formed by electrons may be approximated by a Wigner crystal. The crystal-like electronic order suggests that nanotubes exhibit effects similar to the Mössbauer effect where the momentum of an emitted photon is absorbed by the whole crystal. We show that the circular photovoltaic effect in chiral nanotubes is of the same nature. We obtain the frequency dependence of the photovoltage and characterize its singularities in a broad frequency range where the electron correlations are essential. Our predictions provide a basis for using the photogalvanic effect as a new experimental probe of electron correlations in nanotubes.

Structure factor of interacting one-dimensional helical systems

“…This leads to changes in S(q, ω) which are not captured by the conventional HLL approach. These modifications are particularly nontrivial in the presence of interactions and manifest themselves as power-law singularities whose origin can be traced back to the Fermi edge singularity problem [23][24][25][26][27][28][29][30][31][32].…”

“…Unfortunately, it is not easy to incorporate the nonlinearity in the spectrum within this approach, because the curvature terms lead to interactions between the bosonic Perturbation theory in these interactions produces divergences and a proper resummation is highly non-trivial [32]. Nevertheless, the modifications of threshold features in the response function due to the interactions fall under the paradigm of the Fermi edge singularity problem and are hence tractable [23][24][25][26][27][28][29][30][31][32]. While spin-charge separation complicates the problem for conventional spinful fermions [33,34], helical edge states involve the same number of degrees of freedom as spinless electrons.…”