Multiplexing Read-Out of Charge Qubits by a Superconducting Resonator

• Published in: Chinese physics letters Vol. 33; no. 4; pp. 117 - 120
• Main Author: 韩天一 邓光伟 魏达 郭国平
• Format: Journal Article
• Language: English
• Published: 01.04.2016
• Subjects: 微波谐振腔; 波分复用; 现代光学; 电荷; 读出电路; 超导; 量子比特; 量子计算机
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/33/4/047301

Wavelength division multiplexing （WDM） is widely used in modern optics and electronics. For future quantum computers, the integration of readout is also vitally important. Here we incorporate an idea of WDM to demon- strate multiplexing readout of charge qubits by using a single integrated on-chip superconducting microwave resonator. Two distant qubits formed by two graphene double quantum dots （DQDs） are simultaneously readout by an interconnected superconducting resonator. This readout device is found to have 2 MHz bandwidth and 1.1 x 10-4 e/x/-H-z charge sensitivity. Different frequency gate-modulations, which are used selectively to change the impedance of the qubits, are applied to different DQDs, which results in separated sidebands in the spectrum. These sidebands enable a multiplexing readout for the multi-qubits circuit. This architecture can largely reduce the amount of detectors and can improve the prospect for scaling-up of semiconductor qubits.