Interplay between interferences and electron-electron interactions in epitaxial graphene

Jouault, Benoît; Jabakhanji, Bilal; Camara, Nicolas; Desrat, Wilfried; Conséjo, Christophe; Camassel, Jean

doi:10.1103/physrevb.83.195417

Cited by 57 publications

(74 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At intermediate magnetic fields, between the realms of weak localization and quantum Hall effect, recent measurements highlighted the role of the electron-electron interaction (EEI) on the magnetoconductivity. [6][7][8][9] A complete theory of EEI in graphene is still missing, but it is possible to use the knowledge accumulated in more conventional twodimensional systems like thin metal films or semiconductor heterostructures, for which EEI has been theoretically and experimentally studied over more than three decades [10][11][12][13][14][15]. The quantum correction due to the EEI differs at low and high temperatures.…”

Section: Introductionmentioning

confidence: 99%

“…In particular, in the ballistic regime, EEI depends on the impurity type [23] and can give indications on the microscopic nature of disorder in graphene. Up to now, most of the EEI measurements in graphene have focused on the diffusive regime [6][7][8][9]. The systematic study of EEI correction in this material, from the diffusive to the ballistic regime, associated with quantitative and qualitative comparisons with models of disorder, is still lacking.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Magnetoresistance of disordered graphene: From low to high temperatures

Jabakhanji

Kazazis²,

Desrat

et al. 2014

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

We present the magnetoresistance (MR) of highly doped monolayer graphene layers grown by chemical vapor deposition on 6H-SiC. The magnetotransport studies are performed on a large temperature range, from T = 1.7 K up to room temperature. The MR exhibits a maximum in the temperature range 120 − 240 K. The maximum is observed at intermediate magnetic fields (B = 2 − 6 T), in between the weak localization and the Shubnikov-de Haas regimes. It results from the competition of two mechanisms. First, the low field magnetoresistance increases continuously with T and has a purely classical origin. This positive MR is induced by thermal averaging and finds its physical origin in the energy dependence of the mobility around the Fermi energy. Second, the high field negative MR originates from the electron-electron interaction (EEI). The transition from the diffusive to the ballistic regime is observed. The amplitude of the EEI correction points towards the coexistence of both long and short range disorder in these samples.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Magnetoresistance of disordered graphene: From low to high temperatures

Jabakhanji

Kazazis²,

Desrat

et al. 2014

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…To mention, the MR data reported in this work do not show any sign of WAL behavior (unlike graphene on C face of SiC [17,18]); however, the measured decoherence time is at least s $ 50 ps at the lowest temperatures [ Fig. 1(b)].…”

mentioning

confidence: 96%

“…Measuring S2 in a well-filtered dilution fridge using current levels down to 50 pA to avoid excessive Joule heating we did not find any indication of the crossover to antilocalization nor saturation of L , although a slower temperature dependence was observed for T < 2 K. This is in contrast to the saturation of L reported in Refs. [6,18,20]. S1 was measured in an unfiltered fridge down to 1 K.…”

mentioning

confidence: 99%

Disordered Fermi Liquid in Epitaxial Graphene from Quantum Transport Measurements

et al. 2011

View full text Add to dashboard Cite

We have performed magnetotransport measurements on monolayer epitaxial graphene and analyzed them in the framework of the disordered Fermi liquid theory. We have separated the electron-electron and weak-localization contributions to resistivity and demonstrated the phase coherence over a micrometer length scale, setting the limit of at least 50 ps on the spin relaxation time in this material.Funding Agencies|Swedish Research Council||Foundation for Strategic Research||UK National Measurement Office||EU|

show abstract

“…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.…”

mentioning

confidence: 99%

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

et al. 2017

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

Interplay between interferences and electron-electron interactions in epitaxial graphene

Cited by 57 publications

References 22 publications

Magnetoresistance of disordered graphene: From low to high temperatures

Magnetoresistance of disordered graphene: From low to high temperatures

Disordered Fermi Liquid in Epitaxial Graphene from Quantum Transport Measurements

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

Contact Info

Product

Resources

About

Interplay between interferences and electron-electron interactions in epitaxial graphene

Cited by 57 publications

References 22 publications

Magnetoresistance of disordered graphene: From low to high temperatures

Magnetoresistance of disordered graphene: From low to high temperatures

Disordered Fermi Liquid in Epitaxial Graphene from Quantum Transport Measurements

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

Contact Info

Product

Resources

About

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