Transistor operation and mobility enhancement in top-gated LaAlO3/SrTiO3 heterostructures

Hosoda, Masayuki; Hikita, Y.; Hwang, Harold Y.; Bell, C. H.

doi:10.1063/1.4820449

Cited by 76 publications

(101 citation statements)

References 23 publications

(34 reference statements)

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“…These dynamic techniques include using a conducting atomic force microscope, 12 top gating through the LAO film, 43,44 and using polar solvents. 12,45 One simple fact links these dynamic techniques: they work by modifying the electrostatic potential from the LAO side of the interface.…”

Section: 4647mentioning

confidence: 99%

LaAlO3/SrTiO3interfaces doped with rare-earth ions

et al. 2015

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Section: 4647mentioning

confidence: 99%

LaAlO3/SrTiO3interfaces doped with rare-earth ions

et al. 2015

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“…It is therefore somewhat surprising that a similar strategy has not been adopted to investigate confinement at oxide interfaces thus far. Large area top gated devices have indeed been fabricated using a variety of techniques such as sputtering [24], evaporation [25,26] and in-situ deposition [27,28]. However scaling these structures down has remained a challenge.…”

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Nanoscale Electrostatic Control of Oxide Interfaces

et al. 2015

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We develop a robust and versatile platform to define nanostructures at oxide interfaces via patterned top gates. Using LaAlO3/SrTiO3 as a model system, we demonstrate controllable electrostatic confinement of electrons to nanoscale regions in the conducting interface. The excellent gate response, ultra-low leakage currents, and long term stability of these gates allow us to perform a variety of studies in different device geometries from room temperature down to 50 mK. Using a split-gate device we demonstrate the formation of a narrow conducting channel whose width can be controllably reduced via the application of appropriate gate voltages. We also show that a single narrow gate can be used to induce locally a superconducting to insulating transition. Furthermore, in the superconducting regime we see indications of a gate-voltage controlled Josephson effect.Despite decades of intense study, transition metal oxides continue to reveal fascinating and unexpected physical properties that arise from their highly correlated electrons [1]. Propelled by recent developments in oxides thin film technology it has now become possible to create high quality interfaces between such complex oxides, which reveal a new class of emergent phenomena often non-existent in the constituent materials [2,3]. In particular, there has been a growing interest in interfaces that host a conducting two dimensional electron system (2DES) [4,5]. This 2DES has been shown to support high mobility electrons [5][6][7], magnetism [8] and superconductivity [9]. In addition to this inherently rich phase space, in-situ electrostatic gating can be used not only to alter the carrier density [10], but it can significantly change the spin-orbit coupling (SOC) [11,12] and even drive transitions from a superconducting to an insulating state [13].Bulk transport studies of oxide interfaces have played an important role toward building a better understanding of these new material systems. However, it is becoming increasingly clear that in order to fully grasp the details of the complex coexisting phases at the interface, one must probe the system at much smaller length scales. Recent scanning probe experiments have indeed clearly demonstrated that the electronic properties of the interface can change dramatically over microscopic length scales [14][15][16]. In this context, nanoscale electronic devices could provide direct information on how such strong local variations in physical properties affect mesoscopic charge transport. Perhaps even more exciting is the possibility of discovering and manipulating new electronic states that are predicted to arise from the interplay between confinement, superconductivity and SOC [17]. Furthermore, the ability to locally drive phase transitions at the interface could potentially yield technologically relevant oxide-based nano-electronic devices with novel functionality [18].Existing methods for confinement at the interface involve some form of nanoscale patterning, which renders selected portions of the interface insulati...

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“…The concept of our dual-gate devices is to control the interface and bulk boundary conditions of the asymmetric quantum well via the top 25 and back 6,26 gates, respectively 9,27 . As sketched in Figure 1a, with decreasing top gate voltage (V TG ) at fixed zero back gate voltage (V BG ), the electric field at the interface becomes weaker and the electron envelope wavefunction is pushed away from the interface and its associated scattering, resulting in an increase of the mobility.…”

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confidence: 99%