Parabolic Magnetoresistance from the Interaction Effect in a Two-Dimensional Electron Gas

Paalanen, M. A.; Tsui, D. C.; Hwang, J.C.M.

doi:10.1103/physrevlett.51.2226

Cited by 153 publications

(86 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First to mention are the experiments [22][23][24][25] where the observed temperature dependent negative magnetoresistance was compared to the theoretical prediction for the diffusive regime, Eq.(5). In one of these works 25 the samples used were n-Si/SiGe heterostructures very similar to ours.…”

Section: Results and Analysismentioning

confidence: 99%

Conductivity of a two-dimensional electron gas in a Si/SiGe heterostructure near the metal-insulator transition: Role of the short- and long-range scattering potential

et al. 2003

View full text Add to dashboard Cite

We report the observation of a metal-insulator transition (MIT) in a two-dimensional electron gas (2DEG) in a Si/SiGe heterostructure at zero magnetic field. On going through the MIT we observe the corresponding evolution of the magnetic field induced transition between the insulating phase and the quantum Hall (QH) liquid state in the QH regime. Similar to the previous reports for a GaAs sample, we find that the critical magnetic field needed to produce the transition becomes zero at the critical electron density corresponding to the zero field MIT. The temperature dependence of the conductivity in a metallic-like state at zero field is compared with the theory of the interaction corrections at intermediate and ballistic regimes kBT τ /h ≥ 1. The theory yields a good fit for the linear part of the curve. However the slope of that part of σxx(T ) is about two times smaller than that reported in other 2D systems with similar values of rs. At the same time, the recent theory of magnetoresistance due to electron-electron interaction in the case of arbitrary kBT τ /h, smooth disorder and classically strong fields does not seem to be quite adequate for the description of the parabolic magnetoresistance observed in our samples. We attribute these results to the fact that neither of these theories deals with the whole scattering potential in a sample but leaves either its long range or its short range component out of consideration.

show abstract

Section: Results and Analysismentioning

confidence: 99%

Conductivity of a two-dimensional electron gas in a Si/SiGe heterostructure near the metal-insulator transition: Role of the short- and long-range scattering potential

et al. 2003

View full text Add to dashboard Cite

show abstract

“…Indeed, a T -dependent negative MR was observed in experiments 12,13,14,15,16 and attributed to the interaction effect. However, the majority of experiments 12,13,14 cannot be directly compared with the theory 1,10,11 since they were performed at higher temperatures, T τ 1.…”

Section: Introductionmentioning

confidence: 99%

“…However, the majority of experiments 12,13,14 cannot be directly compared with the theory 1,10,11 since they were performed at higher temperatures, T τ 1. (In high-mobility GaAs heterostructures conventionally used in MR experiments, 1/τ is typically ∼ 100 mK and becomes even smaller with improving quality of samples.)…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Interaction-induced magnetoresistance in a two-dimensional electron gas

2004

View full text Add to dashboard Cite

We study the interaction-induced quantum correction δσ αβ to the conductivity tensor of electrons in two dimensions for arbitrary T τ (where T is the temperature and τ the transport scattering time), magnetic field, and type of disorder. A general theory is developed, allowing us to express δσ αβ in terms of classical propagators ("ballistic diffusons"). The formalism is used to calculate the interaction contribution to the longitudinal and the Hall resistivities in a transverse magnetic field in the whole range of temperature from the diffusive (T τ ≪ 1) to the ballistic (T τ 1) regime, both in smooth disorder and in the presence of short-range scatterers. Further, we apply the formalism to anisotropic systems and demonstrate that the interaction induces novel quantum oscillations in the resistivity of lateral superlattices.

show abstract

“…[16][17][18], and has a value of about c 0 = 0.276. We introduce an additional factor α to fit our resistivities.…”

mentioning

confidence: 99%

Magnetoresistance in a high-mobility two-dimensional electron gas

et al. 2011

View full text Add to dashboard Cite

In a high-mobility two-dimensional electron gas (2DEG) in a GaAs/Al 0.3 Ga 0.7 As quantum well we observe a strong magnetoresistance. In lowering the electron density, the magnetoresistance gets more pronounced and reaches values of more than 300%. We observe that the huge magnetoresistance vanishes when increasing the temperature. An additional density-dependent factor is introduced to be able to fit the parabolic magnetoresistance to the electron-electron interaction correction. Since the first observation of the fractional quantum Hall effect (FQHE) 1,2 the quality and the mobility of the two-dimensional electron gas (2DEG) increased by more than two orders of magnitude. The increased mobility has allowed not only the observation of the FQHE at many different filling factors and smaller magnetic fields but also many new effects. So, microwave-induced oscillations were observed, which were up to now not fully understood. [3][4][5] In weak magnetic fields the increased mobility enabled also the observation of phonon-induced resistance oscillations, which are caused by inelastic scattering between electrons and three-dimensional acoustic phonons. 6,7 The period of phonon-induced oscillations is tunable by an additional dc electric field. 8,9 Also a new type of QHE was enabled in high mobility 2DEGs, the re-entrant integer quantum Hall effect (RIQHE). 10,11 In the regime of the RIQHE the longitudinal resistance between integer filling factors decreases to zero suggesting fractional filling factors, but the corresponding Hall plateaus are quantized at integer values.Here we will present the observation of a huge magnetoresistance in a high mobility 2DEG which depends strongly on electron density and temperature.Our samples were cleaved from a wafer of a high-mobility GaAs/Al 0.3 Ga 0.7 As quantum well grown by molecular-beam epitaxy. The quantum well has a width of 30 nm and is Si-doped from both sides. The 2DEG is located 150 nm beneath the surface and has an electron density of n e ≈ 3.1 × 10 11 cm −2 and a mobility of μ ≈ 11.9 × 10 6 cm 2 /Vs in the dark. The specimens are Hall bars with a total length of 1.2 μm, a width of w = 200 μm and a potential probe spacing of l = 275 μm [see Fig. 1(a)]. The Hall bars were defined by photolithography and wet etching. Different ungated and gated samples were used for the magnetotransport measurements. In the case of the gated sample there is an additional layer of 600 nm PMMA between the Hall bar and the metallic top-gate to avoid leakage current. We apply top-gate voltages up to −6 V to manipulate the electron density. Our measurements were performed in a dilution refrigerator with a base temperature of 20 mK. The measurements were carried out by using low-frequency (13 Hz) lock-in technique.Figure 1(a) shows the longitudinal resistance R xx and the Hall resistance R xy vs. magnetic field B to demonstrate the quality of our samples. A series of different fractional quantum Hall states appears for filling factor ν < 2. We observe also the filling factor ν = 5/2. Over the ...

show abstract

Parabolic Magnetoresistance from the Interaction Effect in a Two-Dimensional Electron Gas

Cited by 153 publications

References 22 publications

Conductivity of a two-dimensional electron gas in a Si/SiGe heterostructure near the metal-insulator transition: Role of the short- and long-range scattering potential

Conductivity of a two-dimensional electron gas in a Si/SiGe heterostructure near the metal-insulator transition: Role of the short- and long-range scattering potential

Interaction-induced magnetoresistance in a two-dimensional electron gas

Magnetoresistance in a high-mobility two-dimensional electron gas

Contact Info

Product

Resources

About