Modulation of over 1014 cm−2 electrons at the SrTiO3/GdTiO3 heterojunction

The polar discontinuity ^[1] and electronic reconstruction at the interface of SrTiO3 and GdTiO3 leads to a unique high two dimensional electron gas (2DEG) of 3×10¹⁴ electron/cm^2[2], that is exactly half of the number of unit cells at the interface. The ability to modulate this high charge density could enable a new class of oxide electronics and plasmonics devices that harness extreme charge density. In this work show how heterostructures field effect transistors can be designed to enable modulation of over 10¹⁴ cm^-2 electron/cm², where represents the highest charge density modulated in any field effector transistor to date.