Photon-assisted tunneling and charge dephasing in a carbon nanotube double quantum dot

Journal article

We report microwave-driven photon-assisted tunneling in a suspended carbon nanotube double quantum dot. From the resonant linewidth at a temperature of 13 mK, the charge-dephasing time is determined to be 280 ± 30 ps. The linewidth is independent of driving frequency, but increases with increasing temperature. The moderate temperature dependence is inconsistent with expectations from electron-phonon coupling alone, but consistent with charge noise arising in the device. The extracted level of charge noise is comparable with that expected from previous measurements of a valley-spin qubit, where it was hypothesized to be the main cause of qubit decoherence. Our results suggest a possible route towards improved valley-spin qubits.

Authors: Laird, E; Mavalankar, A; Pei, T; Gauger, E; Warner, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review B
• Publication date: 2016-06-01
• Acceptance date: 2016-05-13
• DOI: 10.1103/PhysRevB.93.235428
• ISSN: 2469-9969