Probing charge noise in bilayer graphene quantum dots by Landau-Zener-Stückelberg-Majorana spectroscopy

• URL: http://arxiv.org/abs/2605.12257v1
• Date: Tue, 12 May 2026 15:26:22 GMT
• Title: Probing charge noise in bilayer graphene quantum dots by Landau-Zener-Stückelberg-Majorana spectroscopy
• Abstract summary: Charge noise is an important factor limiting qubit coherence and relaxation in solid-state devices.<n>In bilayer graphene (BLG) quantum dots, both the origin and magnitude of charge noise remain largely unexplored.<n>We study a single-particle charge qubit formed in a BLG double quantum dot at frequencies between 5 and 10 GHz.
• Score: 1.1376794606672556
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Charge noise is an important factor limiting qubit coherence and relaxation in solid-state devices. In bilayer graphene (BLG) quantum dots, recently established as a promising platform for spin- and valley-based qubits, both the origin and magnitude of charge noise remain largely unexplored. Here, we investigate high-frequency charge noise using Landau-Zener-Stückelberg-Majorana (LZSM) interference spectroscopy. We study a single-particle charge qubit formed in a BLG double quantum dot at frequencies between 5 and 10 GHz and extract a noise spectral density $S_\varepsilon$ on the order of 0.5-0.9 neV$/\sqrt{\mathrm{Hz}}$. This is comparable to values reported for III-V semiconductor platforms and silicon. From the temperature and frequency dependence of the charge qubit decoherence, we conclude that thermal (Johnson) noise or electron-phonon coupling dominates over two-level fluctuators.

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