Next May 16, Tuesday, at 10:30 we have a QuantaLab Seminars at the INL conference room.
1D physics in metallic line defects of the semiconductor MoSe2
Professor J. M. P. Carmelo1, 2
(1) Department of Physics, University of Minho, P-4710-057 Braga, Portugal
(2) Center of Physics of University of Minho and University of Porto, P-4169-007 Oporto, Portugal
Material line defects in the 2D van der Waals layered semiconductor MoSe2 are 1D structures . Quantum wires and junctions can be isolated in line defects of other transition metal dichalcogenides, which may enable quantum transport measurements and devices.
At low temperatures our scanning tunnelling microscopy and angle resolved photoemission spectroscopy studies find a charge-density wave state for the MoSe2 twin-grain boundaries and that at T _ 300K they exhibit features characteristic of a 1D metal. Our theoretical study uses a pseudofermion representation that was originally introduced for 1D integrable correlated quantum problems [2,3]. The universality of some properties in both integrable and non-integrable 1D correlated models  allows the use of such a representation for finite-energy ! windows in the vicinity of the cusps of the one-particle spectral function of non-integrable correlated problems, which are extensions of corresponding integrable models. Specifically, we use that universality to generate from the pseudofermion dynamical theory of the conventional 1D Hubbard model  a corresponding renormalised theory for that model with additional electron finite-range interactions . The experimental spectral line splits into distinctive spin-like and charge-like spectral features. Their dispersions and (k, w)-plane weight distributions are found to exactly follow those predicted by the non-integrable 1D Hubbard model with suitable electron finite-range interactions associated with the exponent _ _ 0.78 found experimentally for the density of states suppression, |!|_.
 Y. Ma, H. C. Diaz, J. Avila, C. Chen, V. Kalappattil, R. Das, M.-H. Phan, T. ˇCadeˇz, J. M. P. Carmelo, M. C. Asensio, and M. Batzill
Nature Communications 8, 14231 doi: 10.1038/ncomms14231 (2017).
Open access in http://www.nature.com/articles/ncomms14231
 J. M. P. Carmelo and T. Prosen
Nuclear Physics B 914, 62-98 (2017).
Open access in http://www.sciencedirect.com/science/article/pii/S0550321316303492
 J. M. P. Carmelo and T. ˇCadeˇz
Nuclear Physics B 914, 461-552 (2017).