| 000 | 02326ntm a22004217a 4500 | ||
|---|---|---|---|
| 003 | AT-ISTA | ||
| 005 | 20250911124310.0 | ||
| 008 | 250911s2024 au ||||| m||| 00| 0 eng d | ||
| 040 | _cISTA | ||
| 100 |
_aSagi, Oliver _91084209 |
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| 245 | _aHybrid circuits on planar Germanium | ||
| 260 |
_bInstitute of Science and Technology Austria _c2024 |
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| 500 | _aThesis | ||
| 505 | _aAbstract | ||
| 505 | _aAcknowledgements | ||
| 505 | _aAbout the Author | ||
| 505 | _aList of Collaborators and Publications | ||
| 505 | _aTable of Contents | ||
| 505 | _aList of Figures | ||
| 505 | _aList of Tables | ||
| 505 | _a1 Motivation | ||
| 505 | _a2 Theoretical background | ||
| 505 | _a3 Measurement setup | ||
| 505 | _a4 Hybrid Josephson junctions | ||
| 505 | _a5 CPW resonators on SiGe substrate | ||
| 505 | _a6 Towards Ge gatemons | ||
| 505 | _a7 Ge Gatemons | ||
| 505 | _a8 Outlook and Conclusions | ||
| 505 | _aBibliography | ||
| 505 | _aA Additional resonator data | ||
| 505 | _aB Effect of gate material on JJs | ||
| 505 | _aC Reference measurements on Si transmons | ||
| 505 | _aD Rabi anomalies | ||
| 505 | _aE Fabrication recipes | ||
| 520 | _aThe new era of Ge has opened up new possibilities in quantum computing. The maturity of Ge spin qubits is unquestioned, while hybrid semiconductor-superconductor Ge circuits are on track to enter the game. Gate-tunable transmons (gatemons) employing semiconductor Josephson junctions have recently emerged as building blocks for such hybrid quantum circuits. In this thesis, we present a gatemon fabricated in planar Germanium. We induce superconductivity in a two-dimensional hole gas by evaporating aluminum atop a thin spacer, which separates the superconductor from the Ge quantum well. The Josephson junction is then integrated into an Xmon circuit and capacitively coupled to a transmission line resonator. We showcase the qubit tunability in a broad frequency range with resonator and two-tone spectroscopy. Time-domain characterizations reveal energy relaxation and coherence times up to 75 ns. Our results, combined with the recent advances in the spin qubit field, pave the way towards novel hybrid and protected qubits in a group IV, CMOS-compatible material. | ||
| 856 | _uhttps://doi.org/10.15479/at:ista:18076 | ||
| 942 | _2ddc | ||
| 999 |
_c768045 _d768045 |
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