Electric field effects in graphene/LaAlO<sub>3</sub>/SrTiO<sub>3</sub> heterostructures and nanostructures

Huang, Mengchen; Jnawali, Giriraj; Hsu, Jen‐Feng; Dhingra, Shonali; Lee, Hyungwoo; Ryu, Sangwoo; Bi, Feng; Ghahari, Fereshte; Ravichandran, Jayakanth; Chen, Lu; Kim, Philip; Eom, Chang‐Beom; D’Urso, Brian; Irvin, Patrick; Levy, Jeremy

doi:10.1063/1.4916098

Cited by 20 publications

(21 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has recently been demonstrated that this technique can also be used to create devices on graphene/LaAlO 3 /SrTiO 3 heterostructures. [43] Since the coexistence of multiple phases in oxide heterostructures is largely associated with a manifold of electronic degrees of 4 freedom and strong correlations between them, unique interactions with the nearby graphene layer may be expected.Here we report fabrication and magnetotransport characterization of high mobility graphene fieldeffect devices on a complex-oxide heterostructure, LaAlO 3 /SrTiO 3 . These devices exhibit quantum transport signatures such as anomalous quantum Hall effect and WAL behavior over a broad temperature range.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO₃/SrTiO₃ Heterostructures

et al. 2017

Self Cite

View full text Add to dashboard Cite

2Weak localization (WL) and weak antilocalization (WAL) are quantum interference effects [1][2][3][4] resulting from electron phase coherence and spin-orbit interactions in 2-dimensional (2D) electron systems. WL results from constructive interference between pairs of time-reversed closed-loop electron trajectories and provides a positive correction to the Drude resistivity. [2, 4] Spin-orbit coupling (SOC) leads to suppressed backscattering due to destructive interference, leading to WAL and a negative correction to the Drude resistivity.[3]The intrinsic SOC of graphene is weak; [5] however, charge carriers in graphene possess a pseudospin degree of freedom, which arises from the degeneracy introduced by the two inequivalent atomic sites per unit cell in the graphene honeycomb lattice being comprised of A and B sublattices[ Figure 1(a) and (b)]. [6, 7] Recent discovery of unique quantum transport phenomena in graphene, such as unconventional half-integer quantum Hall effect [7, 8] and Klein tunneling [9][10][11] is a direct consequence of non-trivial Berry phase of ! induced by pseudospin rotation. Pseudospin in graphene can be utilized to store and manipulate information, which is analogous to the spin degree of freedom in spintronics. [12][13][14][15][16] Because of pseudospin rotation, each scattering process has a phase difference of ! between two time reversal pair in a closed quantum diffusive path. This results in destructive interference that suppresses backscattering, leading to WAL in graphene, which is analogous to the role of SOC (Figure 1(c) and (d)) in ordinary semiconductors. WAL is theoretically expected in graphene in the absence of inter-valley and chirality breaking scattering. [17] Most studies have not presented clear evidence of WAL via negative magnetoconductance, [18][19][20][21][22] most likely due to presence of point defects in graphene samples that locally break the sublattice degeneracy and smooth out !-phase contribution. Experimental signatures of WAL observed in high-quality epitaxial graphene samples are attributed to suppressed point defects.[23]Interestingly, a WL to WAL transition is achieved in high quality exfoliated samples [24] by decreasing the ratio of the dephasing length to the symmetry-breaking length via decoherence and carrier-density control. 3Preservation of pseudospin quantum interference up to room temperature (RT) is of fundamental importance for a variety of proposed applications, [12-16, 25, 26] but thermal perturbations typically suppress the phase coherence and hinder practical use of the devices. RT operation can be achieved if the high graphene mobility is consistently maintained over a broad temperature range and phonon-scattering contribution is significantly reduced. The mobility of graphene field-effect devices fabricated on SiO 2 /Si substrates is typically reduced at RT due to scattering with surface polar modes. [20,27,28] A significant improvement in quality was achieved by fabricating graphene devices on hexagonal-boron nitride (hBN) ...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO₃/SrTiO₃ Heterostructures

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…This writing technique offers the utmost spatial resolution with line widths as small as 2 nm [10]. While this technique does not allow for top gating, the successful fabrication of field-effect transistors [11,12], single-electron transistors [13], and a series other devices by using this so-called sketch-based technique has been reported (for an overview see [14]). …”

mentioning

confidence: 99%

Field-Effect Transistors with Submicrometer Gate Lengths Fabricated fromLaAlO3−SrTiO3-Based Heterostructures

et al. 2015

View full text Add to dashboard Cite

show abstract

“…More interestingly, decoupled structures combining graphene with LAO/STO junctions represent an exciting platform in which novel phenomena may emerge from the strong electronic coupling of the respective 2DEGs. Recently, the transport properties of hybrid devices obtained by depositing graphene on a LAO/STO oxide junction hosting a 4 nm-deep 2DEG has been studied [18,19].…”

Section: Introductionmentioning

confidence: 99%

Plasmons at the LaAlO3/SrTiO3 interface and in the graphene- LaAlO3 / SrTiO
Faridi
¹
,
Asgari
²

2017
Phys. Rev. B
14
0
12
0
View full text Add to dashboard Cite

We study plasmon modes of the two-dimensional electron gas residing at the interface of band insulators LaAlO3 and SrTiO3 (LAO/STO) and the plasmon excitations of graphene-LAO/STO double layer as well. Considering the electron-electron interaction within random phase approximation, we calculate the plasmon dispersions of both systems numerically and in the long wavelength limit analytical expressions for collective modes are found. One optical mode and two (three) acoustic modes are predicted for the LAO/STO (graphene-LAO/STO) system where only the uppermost acoustic mode of both systems can emerge above the electron-hole continuum depending on the characteristics of each system. In the case of LAO/STO interface, thanks to the spatial separation between t2g orbitals, the upper acoustic mode might be undamped at the long wavelength limit depending on the exact value of the dielectric constant of SrTiO3. Same as other double layer systems, the interlayer distance for the graphene-LAO/STO system plays a crucial role in damping the upper acoustic mode. Faster damping of all plasmon modes of the present double layer system in comparison with the ones with conventional two-dimensional electron gas instead of t2g electron gas is also found due to heavier effective masses of the gas and also stronger interlayer Coulomb interaction.

show abstract

Electric field effects in graphene/LaAlO₃/SrTiO₃ heterostructures and nanostructures

Cited by 20 publications

References 40 publications

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO₃/SrTiO₃ Heterostructures

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO₃/SrTiO₃ Heterostructures

Field-Effect Transistors with Submicrometer Gate Lengths Fabricated fromLaAlO3−SrTiO3-Based Heterostructures

Plasmons at the LaAlO3/SrTiO3 interface and in the graphene- LaAlO3 / SrTiO
Faridi
¹
,
Asgari
²

2017
Phys. Rev. B
14
0
12
0
View full text Add to dashboard Cite

Contact Info

Product

Resources

About

Electric field effects in graphene/LaAlO3/SrTiO3 heterostructures and nanostructures

Cited by 20 publications

References 40 publications

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO3/SrTiO3 Heterostructures

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO3/SrTiO3 Heterostructures

Field-Effect Transistors with Submicrometer Gate Lengths Fabricated fromLaAlO3−SrTiO3-Based Heterostructures

Plasmons at the LaAlO3/SrTiO3 interface and in the graphene- LaAlO3 / SrTiOFaridi1, Asgari2 2017Phys. Rev. B140120View full textAdd to dashboardCite

Contact Info

Product

Resources

About

Electric field effects in graphene/LaAlO₃/SrTiO₃ heterostructures and nanostructures

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO₃/SrTiO₃ Heterostructures

Room‐Temperature Quantum Transport Signatures in Graphene/LaAlO₃/SrTiO₃ Heterostructures

Plasmons at the LaAlO3/SrTiO3 interface and in the graphene- LaAlO3 / SrTiO
Faridi
¹
,
Asgari
²

2017
Phys. Rev. B
14
0
12
0
View full text Add to dashboard Cite