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Dey, Bashab ; Schliemann, John

Role of anisotropic confining potential and elliptical driving in dynamics of a Ge hole qubit

Dey, Bashab und Schliemann, John (2025) Role of anisotropic confining potential and elliptical driving in dynamics of a Ge hole qubit. Journal of Physics: Condensed Matter 37 (15), S. 155702.

Veröffentlichungsdatum dieses Volltextes: 20 Mai 2025 04:27
Artikel
DOI zum Zitieren dieses Dokuments: 10.5283/epub.76694


Zusammenfassung

The squeezing of a Ge planar quantum dot enhances the Rabi frequency of electric dipole spin resonance by several orders of magnitude due to a strong Direct Rashba spin–orbit interaction in such geometries (Bosco et al 2021 Phys. Rev. B 104 115425). We investigate the geometric effect of an elliptical (squeezed) confinement and its interplay with the polarization of driving field in determining ...

The squeezing of a Ge planar quantum dot enhances the Rabi frequency of electric dipole spin resonance by several orders of magnitude due to a strong Direct Rashba spin–orbit interaction in such geometries (Bosco et al 2021 Phys. Rev. B 104 115425). We investigate the geometric effect of an elliptical (squeezed) confinement and its interplay with the polarization of driving field in determining the Rabi frequency of a heavy-hole qubit in a planar Ge quantum dot. To calculate the Rabi frequency, we consider only the p-linear SOIs viz. electron-like Rashba, hole-like Rashba and hole-like Dresselhaus which are claimed to be the dominant ones by recent studies on planar Ge heterostructures. We derive approximate analytical expressions of the Rabi frequency using a Schrieffer–Wolff transformation for small SOI and driving strengths. Firstly, for an out-of-plane magnetic field with magnitude B, we get an operating region with respect to B, squeezing and polarization parameters where the qubit can be operated to obtain 'clean' Rabi flips. On and close to the boundaries of the region, the higher orbital levels strongly interfere with the two-level qubit subspace and destroy the Rabi oscillations, thereby putting a limitation on squeezing of the confinement. The Rabi frequency shows different behaviour for electron-like and hole-like Rashba SOIs. It vanishes for right (left) circular polarization in presence of purely electron-like (hole-like) Rashba SOI in a circular confinement. For both in- and out-of-plane magnetic fields, higher Rabi frequencies are achieved for squeezed configurations when the ellipses of polarization and the confinement equipotential have their major axes aligned but with different eccentricities. We also deduce a simple formula to calculate the effective heavy hole mass by measuring the Rabi frequencies using this setup.



Beteiligte Einrichtungen


Details

DokumentenartArtikel
Titel eines Journals oder einer ZeitschriftJournal of Physics: Condensed Matter
Verlag:IOP Publishimg
Band:37
Nummer des Zeitschriftenheftes oder des Kapitels:15
Seitenbereich:S. 155702
Datum4 März 2025
InstitutionenPhysik > Institut für Theoretische Physik > Lehrstuhl Professor Grifoni > Arbeitsgruppe John Schliemann
Identifikationsnummer
WertTyp
10.1088/1361-648X/adb927DOI
Stichwörter / Keywordsspin qubits, elliptical quantum dot, Floquet time evolution
Dewey-Dezimal-Klassifikation500 Naturwissenschaften und Mathematik > 530 Physik
StatusVeröffentlicht
BegutachtetJa, diese Version wurde begutachtet
An der Universität Regensburg entstandenJa
URN der UB Regensburgurn:nbn:de:bvb:355-epub-766941
Dokumenten-ID76694

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