Electrode-induced lattice distortions in GaAs multi-quantum-dot arrays

Pateras, Anastasios; Carnis, Jérôme; Mukhopadhyay, U.; Richard, Marie-Ingrid; Leake, Steven; Schülli, Tobias U.; Reichl, Christian; Wegscheider, Werner; Dehollain, Juan Pablo; Vandersypen, L. M. K.; Evans, Paul G.

doi:10.1557/jmr.2019.61

“…In our system, this is mostly caused by the surface electrodes, as GaAs and Al x Ga 1−x As are essentially lattice-matched for x = 0.3 (mismatch ∼ 4.26 × 10 −4 ). Independent work carried out using wafers and electrodes similar to our own measured a stress-induced tilt of the crystallographic planes of about 0.015 • , matching a stress of 57 MPa, and therefore corresponding to a maximum in-place strain of xx of ∼ 4 × 10 −5 [41,42]. It is important to highlight, however, that these measurements were carried out at room temperature, and that it is expected that the strain is reduced by up to factor of 2 when cooled down to cryogenic temperatures [43].…”

Section: Having Shown Our Technique To Work Successfully In 2dsupporting

confidence: 53%

Decoupling of the many-body effects from the electron mass in GaAs by means of reduced dimensionality

Vianez¹,

Jin²,

Tan³

et al. 2021

Preprint

0

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Determining the (bare) electron mass m0 in crystals is often hindered by many-body effects since Fermi-liquid physics renormalises the band mass, making the observed effective mass m * depend on density. Here, we use a one-dimensional (1D) geometry to amplify the effect of interactions, forcing the electrons to form a nonlinear Luttinger liquid with separate holon and spinon bands, therefore separating the interaction effects from m0. Measuring the spectral function of gated quantum wires formed in GaAs by means of magnetotunnelling spectroscopy and interpreting them using the 1D Fermi-Hubbard model, we obtain m0 = (0.0525 ± 0.0015)me in this material, where me is the free-electron mass. By varying the density in the wires, we change the interaction parameter rs in the range from ∼1-4 and show that m0 remains constant. The determined value of m0 is ∼ 22% lighter than observed in GaAs in geometries of higher dimensionality D (D > 1), consistent with the quasi-particle picture of a Fermi liquid that makes electrons heavier in the presence of interactions.

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“…5a alone. For additional effects that could affect the value of m 0 , see [22] which includes [16,[49][50][51][52][53][54][55][56][57].…”

Section: Discussionmentioning

confidence: 99%

Decoupling of the many-body effects from the electron mass in GaAs by means of reduced dimensionality

Vianez¹,

Jin²,

Tan³

et al. 2023

Phys. Rev. B

1

0

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Determining the (bare) electron mass m0 in crystals is often hindered by many-body effects since Fermi-liquid physics renormalises the band mass, making the observed effective mass m * depend on density. Here, we use a one-dimensional (1D) geometry to amplify the effect of interactions, forcing the electrons to form a nonlinear Luttinger liquid with separate holon and spinon bands, therefore separating the interaction effects from m0. Measuring the spectral function of gated quantum wires formed in GaAs by means of magnetotunnelling spectroscopy and interpreting them using the 1D Fermi-Hubbard model, we obtain m0 = (0.0525 ± 0.0015)me in this material, where me is the free-electron mass. By varying the density in the wires, we change the interaction parameter rs in the range from ∼1-4 and show that m0 remains constant. The determined value of m0 is ∼ 22% lighter than observed in GaAs in geometries of higher dimensionality D (D > 1), consistent with the quasi-particle picture of a Fermi liquid that makes electrons heavier in the presence of interactions.

show abstract