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

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

Pateras, Anastasios (University of Wisconsin-Madison)
Carnis, Jérôme (Aix Marseille Université)
Mukhopadhyay, U. (TU Delft QCD/Vandersypen Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Richard, Marie Ingrid (Aix Marseille Université)
Leake, Steven J. (European Synchrotron Radiation Facility)
Schülli, Tobias U. (European Synchrotron Radiation Facility)
Reichl, Christian (ETH Zürich)
Wegscheider, Werner (ETH Zürich)
Dehollain Lorenzana, J.P. (TU Delft QCD/Vandersypen Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Vandersypen, L.M.K. (TU Delft QCD/Vandersypen Lab; TU Delft QN/Vandersypen Lab; Kavli institute of nanoscience Delft)
Evans, Paul G. (University of Wisconsin-Madison)

2019

Increasing the number of quantum bits while preserving precise control of their quantum electronic properties is a significant challenge in materials design for the development of semiconductor quantum computing devices. Semiconductor heterostructures can host multiple quantum dots that are electrostatically defined by voltages applied to an array of metallic nanoelectrodes. The structural distortion of multiple-quantum-dot devices due to elastic stress associated with the electrodes has been difficult to predict because of the large micrometer-scale overall sizes of the devices, the complex spatial arrangement of the electrodes, and the sensitive dependence of the magnitude and spatial variation of the stress on processing conditions. Synchrotron X-ray nanobeam Bragg diffraction studies of a GaAs/AlGaAs heterostructure reveal the magnitude and nanoscale variation of these distortions. Investigations of individual linear electrodes reveal lattice tilts consistent with a 28-MPa compressive residual stress in the electrodes. The angular magnitude of the tilts varies by up to 20% over distances of less than 200 nm along the length of the electrodes, consistent with heterogeneity in the metal residual stress. A similar variation of the crystal tilt is observed in multiple-quantum-dot devices, due to a combination of the variation of the stress and the complex electrode arrangement. The heterogeneity in particular can lead to significant challenges in the scaling of multiple-quantum-dot devices due to differences between the charging energies of dots and uncertainty in the potential energy landscape. Alternatively, if incorporated in design, stress presents a new degree of freedom in device fabrication.

devices
nanostructure
X-ray diffraction (XRD)

http://resolver.tudelft.nl/uuid:8160271c-5694-41eb-985b-af7ba4347e31

https://doi.org/10.1557/jmr.2019.61

2019-09-06

0884-2914

Journal of Materials Research, 34 (8), 1291-1301

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2019 Anastasios Pateras, Jérôme Carnis, U. Mukhopadhyay, Marie Ingrid Richard, Steven J. Leake, Tobias U. Schülli, Christian Reichl, Werner Wegscheider, J.P. Dehollain Lorenzana, L.M.K. Vandersypen, Paul G. Evans