Ultrafast Melting of Charge-Density-Wave Order and a Transient Metastable State in 4Hb-TaS2
4Hb-TaS2 is a natural heterostructure of correlated (T) and superconducting (H) layers. Using time- and angle-resolved photoemission spectroscopy, we observe a narrow feature slightly above the Fermi level on the T-layer termination, corresponding to the band edge of a charge-density-wave (CDW)-gapped electron-like dis...