Relationship between conductance fluctuation and weak localization in graphene

Abstract

The relationship between the universal conductance fluctuation and the weak localization effect in monolayer graphene is investigated. By comparing experimental results with the predictions of the weak localization theory for graphene, we find that the ratio of the elastic intervalley scattering time to the inelastic dephasing time varies in accordance with the conductance fluctuation; this is a clear evidence connecting the universal conductance fluctuation with the weak localization effect. We also find a series of scattering lengths that are related to the phase shifts caused by magnetic flux by Fourier analysis.

Temperature dependence of universal conductance fluctuation due to development of weak localization in graphene

“…Figure 2 (a) shows ∆ρ xx as a function of B for LMax (V g = 19.1 V) and LMin (V g = 19.8 V). As previously demonstrated [19], ∆ρ xx is reduced by a larger amount for LMax than for LMin. Figure 2 (b) shows ∆ρ xx for LMax (V g = 19.1 V) as a function of B for several values of T .…”

“…Detailed fitting procedures are available in Ref. [19]. In graphene, weak electron-phonon scattering is expected [25,26], and electron-electron scattering is considered to be the major source of dephasing [7,8].…”

“…There has been much discussion on their relationship [13,14,15], and it is known that the inelastic dephasing length obtained separately from both UCF and WL analysis are in agreement [16,17,18]. Recently, an essential development in understanding the relationship between UCF and WL has been made: the cause of the UCF can be attributed to WL [19] in monolayer graphene. From this reference, the ratio of inelastic scattering (dephasing) time τ ϕ to intervalley scattering time τ i , τ ϕ /τ i , which causes the WL correction to conductance, varies with the UCF.…”

Disorder and Weak Localization near Charge Neutral Point in Ti‐cleaned Single‐Layer Graphene

“…We also use this Ti‐cleaning on a correlation analysis method between the wavenumber shifts of the G and 2D Raman mode . Magneto‐transport is a powerful tool for examining the disorder effects and electrical characteristics of 2D electron systems such as graphene . Recently, we investigated the relationship between intervalley scattering and universal conductance fluctuations in graphene, and gas adsorption on the surface of graphene, by means of magneto‐transport.…”

“…Magneto‐transport is a powerful tool for examining the disorder effects and electrical characteristics of 2D electron systems such as graphene . Recently, we investigated the relationship between intervalley scattering and universal conductance fluctuations in graphene, and gas adsorption on the surface of graphene, by means of magneto‐transport. Furthermore, by examining the temperature dependence of the carrier concentration through Hall measurements, we estimate the strength of the disorder potential for CVD single‐layer graphene and compare it to the case of epitaxial graphene.…”