A gate tunable transmon qubit in planar Ge
Abstract: Gate-tunable transmons (gatemons) employing semiconductor Josephson junctions have recently emerged as building blocks for hybrid quantum circuits. In this study, 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.
- R. Aguado, A perspective on semiconductor-based superconducting qubits, Applied Physics Letters 117, 240501 (2020).
- T. D. Vethaak, Silicide-based josephson field effect transistors for superconducting qubits (2022), arXiv:2209.02721 [physics.app-ph] .
- C. W. J. Beenakker, Universal limit of critical-current fluctuations in mesoscopic josephson junctions, Phys. Rev. Lett. 67, 3836 (1991).
- S. Burkhard, Optimization of transmon design for longer coherence time (2012).
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