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Nicholas, R.J.; Haug, Rolf J.; Klitzing, K. von; Weimann, G.

doi:10.1103/physrevb.37.1294

Cited by 270 publications

(196 citation statements)

References 26 publications

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“…The g-factor obtained from the angular evolution of MISO (see next section) is g MISO =0.15-0.25. The obtained g-factors are close to the bare g-factor in GaAs quantum wells 39,40 and significantly smaller the one obtained from QPMR 28 and SdH oscillations [41][42][43] in GaAs quantum well with a single populated subband. Figure 5(c) shows the angular dependence of the quantum scattering times τ (i)…”

Section: Qpmr In Tilted Magnetic Fieldsupporting

confidence: 51%

Quantum electron transport in magnetically entangled subbands

2017

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Transport properties of highly mobile 2D electrons in symmetric GaAs quantum wells with two populated subbands placed in titled magnetic fields are studied at high temperatures. Quantum positive magnetoresistance (QPMR) and magneto-intersubbands resistance oscillations (MISO) are observed in quantizing magnetic fields, B ⊥ , applied perpendicular to the 2D layer. QPMR displays contributions from electrons with considerably different quantum lifetimes, τ (1,2) q , confirming the presence of two subbands in the studied system. MISO evolution with B ⊥ agrees with the obtained quantum scattering times only if an additional reduction of the MISO magnitude is applied at small magnetic fields. This indicates the presence of a yet unknown mechanism leading to MISO damping. Application of in-plane magnetic field produces a strong decrease of both QPMR and MISO magnitude. The reduction of QPMR is explained by spin splitting of Landau levels indicating g-factor, g ≈0.4, which is considerably less than the g-factor found in GaAs quantum well with a single subband populated. In contrast to QPMR the decrease of MISO magnitude is largely related to the in-plane magnetic field induced entanglement between quantum levels in different subbands that, in addition, increases the MISO period.

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Section: Qpmr In Tilted Magnetic Fieldsupporting

confidence: 51%

Quantum electron transport in magnetically entangled subbands

2017

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“…3 can be explained by the overlapping of spin-up and spin-down levels from the adjacent Landau levels due to Zeeman splitting in the applied B. 33 However, from our experiments the estimated g * < 0.2, which is very low for spin splitting. In addition, although the resistance decreases in a parallel field, the R max value does not change by an order of magnitude.…”

Section: Resistance At the Cnp In Tilted Magnetic Fieldcontrasting

confidence: 39%

Transport gap in suspended bilayer graphene at zero magnetic field

et al. 2012

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We report a change of three orders of magnitude in the resistance of a suspended bilayer graphene flake which varies from a few k in the high-carrier-density regime to several M around the charge neutrality point (CNP). The corresponding transport gap is 8 meV at 0.3 K. The sequence of quantum Hall plateaus appearing at filling factor ν = 2 followed by ν = 1 suggests that the observed gap is caused by the symmetry breaking of the lowest Landau level. Investigation of the gap in a tilted magnetic fields indicates that the resistance at the CNP shows a weak linear decrease for increasing total magnetic field. Those observations are in agreement with a spontaneous valley splitting at zero magnetic field followed by splitting of the spins originating from different valleys with increasing magnetic field. Both the transport gap and B field response point toward the spin-polarized layer-antiferromagnetic state as the ground state in the bilayer graphene sample. The observed nontrivial dependence of the gap value on the normal component of B suggests possible exchange mechanisms in the system.

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“…3(a) and was not observed in the activation energy measurements where the effective electron |g|-factors were obtained to be 5.3 and 2.5 at ν = 3 and 5, respectively. 25 The enhancement of g-factor up to 15 was observed at ν = 3 at B ≈ 6 T in GaAs/Al x Ga 1−x As single heterojunction with a δ layer of Be acceptors located at a well-defined distance from the interfaces. 22 It is tempting to associate the shrinking of the |g * eff | at ν = 3 with the multiple low-energy spin excitations.…”

Section: Resultsmentioning

confidence: 98%

Exchange energy enhancedg-factors obtained from Landau fan diagrams at low magnetic fields

et al. 2013

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We report on measurement of the electron-hole effective g-factors (g * eff ) depending on electron filling factors ν from magnetophotoluminescence spectroscopy at low magnetic fields B < 1 T in low electron density regime in a GaAs/Al 0.33 Ga 0.67 As-gated quantum well. Enhancement of g * eff at odd ν is observed. The oscillatory behavior of g * eff is compared with results of a theory that takes into account the lowest-order exchange interaction of the screened Coulomb interaction. Good agreement of the observed g * eff with theoretical results is obtained except ν at around 3. The enhancement of g * eff at even ν with decrease in electron density has not been observed.

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Exchange enhancement of the spin splitting in a GaAs-GaxAl1
R.J. Nicholas
¹
,
Rolf J. Haug
²
,
K. von Klitzing
³

et al.

Cited by 270 publications

References 26 publications

Quantum electron transport in magnetically entangled subbands

Quantum electron transport in magnetically entangled subbands

Transport gap in suspended bilayer graphene at zero magnetic field

Exchange energy enhancedg-factors obtained from Landau fan diagrams at low magnetic fields

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Exchange enhancement of the spin splitting in a GaAs-GaxAl1R.J. Nicholas1, Rolf J. Haug2, K. von Klitzing3 et al.

Cited by 270 publications

References 26 publications

Quantum electron transport in magnetically entangled subbands

Quantum electron transport in magnetically entangled subbands

Transport gap in suspended bilayer graphene at zero magnetic field

Exchange energy enhancedg-factors obtained from Landau fan diagrams at low magnetic fields

Contact Info

Product

Resources

About

Exchange enhancement of the spin splitting in a GaAs-GaxAl1
R.J. Nicholas
¹
,
Rolf J. Haug
²
,
K. von Klitzing
³

et al.