Possible spin-charge separation of the Tomonaga-Luttinger liquid on Bi/InSb(001)

Detailed surface electronic structure on the Bi/InSb(001) surface hosting Tomonaga-Luttinger liquid was observed by angle-resolved photoelectron spectroscopy (ARPES) with synchrotron radiation. ARPES energy distribution curves (EDCs) around the Fermi level indicated the two separate features dispersing with different Fermi velocity but approaching each other. Two possible scenarios, elemental excitations from separate spin/charge terms and those from independent two surface bands, are discussed based on the experimental results.