Single-shot readout in graphene quantum dots

• URL: http://arxiv.org/abs/2112.12091v1
• Date: Wed, 22 Dec 2021 17:48:32 GMT
• Title: Single-shot readout in graphene quantum dots
• Authors: Lisa Maria G\"achter, Rebekka Garreis, Chuyao Tong, Max Josef Ruckriegel, Benedikt Kratochwil, Folkert Kornelis de Vries, Annika Kurzmann, Kenji Watanabe, Takashi Taniguchi, Thomas Ihn, Klaus Ensslin and Wister Wei Huang
• Abstract summary: We demonstrate two different experimental approaches to measure the decay times of excited states. We find that the relaxation time of the excited state is of the order of milliseconds. We perform single-shot readout of our two-level system with a visibility of $87.1%$, which is an important step for developing a quantum information processor in graphene.
• Score: 0.305491665195957
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Electrostatically defined quantum dots in bilayer graphene offer a promising platform for spin qubits with presumably long coherence times due to low spin-orbit coupling and low nuclear spin density. We demonstrate two different experimental approaches to measure the decay times of excited states. The first is based on direct current measurements through the quantum device. Pulse sequences are applied to control the occupation of ground and excited states. We observe a lower bound for the excited state decay on the order of hundred microseconds. The second approach employs a capacitively coupled charge sensor to study the time dynamics of the excited state using the Elzerman technique. We find that the relaxation time of the excited state is of the order of milliseconds. We perform single-shot readout of our two-level system with a visibility of $87.1\%$, which is an important step for developing a quantum information processor in graphene.

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