*Special day / time / location
The discovery of a two-dimensional electron gas (2DEG) at the LaAlO3/SrTiO3 interface has set a new platform for all-oxide electronics which could potentially exhibit the interplay among charge, spin, orbital, superconductivity, ferromagnetism and ferroelectricity. We have found that by using UV irradiation, 2DEGs can also be formed at the bare surfaces of transition metal oxides: SrTiO3, KTaO3 and ferroelectric Nb-doped KTaO3. Their electronic band structures can be measured directly by using angle-resolved photoemission spectroscopy. In this talk, I will explain about how these 2DEGs can be created and controlled. I will also discuss about their interesting features including a) our model about orbitally-enhanced spin texture, b) the so-called negative electronic compressibility where the chemical potential reduces upon increasing carrier density and c) the change across ferroelectric transition. If time permits, I will briefly describe about our studies of electrons at the surfaces of transition metal dichalcogenides: MoS2 and WSe2.
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- P.D.C. King, et al. Nat. Commun. 5; 3414 (2014)
- T. Eknapakul, et al. Nano Lett. 14; 1312 (2014).
- J. M. Riley, W. Meevasana, et al. Nat. Nanotechnol. 10; 1043-1047 (2015)