Charge-density wave transition of 1T-VSe2 studied by angle-resolved photoemission spectroscopy -: art. no. 155108

High-resolution angle-resolved photoemission spectroscopy (ARPES) has been performed on a layered transition-metal dichalcogenide (TMDC) 1T-VSe2 to study the (4x4) charge-density wave (CDW) mechanism. We observed a partial Fermi-surface (FS) nesting on the electronlike FS centered at the M (L) point. The spectral weight near E-F is considerably suppressed below the transition temperature (T-c=110 K) around the nested portion, while a negligible spectral change is observed even across T-c in other portions of FS. This suggests that the CDW transition in 1T-VSe2 is caused by the three-dimensional FS nesting. Implications are discussed in relation to the physical properties of 1T-VSe2 as well as the ARPES results of other TMDC's.