Faculté des sciences

Evidence for an Excitonic Insulator Phase in 1T–TaS2

Cercellier, H. ; Monney, Claude ; Clerc, F. ; Battaglia, Corsin ; Despont, Laurent ; Garnier, Michael Bernard Gunnar ; Beck, H. ; Aebi, Philipp ; Patthey, L. ; Berger, H. ; Forró, L.

In: Physical Review Letters, 2007, vol. 99, no. 146403, p. 1-4

We present a new high-resolution angle-resolved photoemission study of 1T–TaS2 in both its room-temperature, normal phase and its low-temperature, charge-density wave phase. At low temperature the photoemission spectra are strongly modified, with large band renormalizations at high-symmetry points of the Brillouin zone and a very large transfer of spectral weight to backfolded... Plus

Ajouter à la liste personnelle
    Summary
    We present a new high-resolution angle-resolved photoemission study of 1T–TaS2 in both its room-temperature, normal phase and its low-temperature, charge-density wave phase. At low temperature the photoemission spectra are strongly modified, with large band renormalizations at high-symmetry points of the Brillouin zone and a very large transfer of spectral weight to backfolded bands. A calculation of the theoretical spectral function for an excitonic insulator phase reproduces the experimental features with very good agreement. This gives strong evidence in favor of the excitonic insulator scenario as a driving force for the charge-density wave transition in 1T–TaS2.