1. Multi-level quantum noise spectroscopy
- Author
-
Fei Yan, Jochen Braumüller, Alexander Melville, Youngkyu Sung, Roni Winik, Morten Kjaergaard, Philip Krantz, Bethany Niedzielski, Terry P. Orlando, William D. Oliver, Jonilyn Yoder, Simon Gustavsson, Antti Vepsäläinen, David Kim, Joel I-Jan Wang, Mollie Schwartz, and Andreas Bengtsson
- Subjects
Quantum information ,Computer science ,Science ,General Physics and Astronomy ,FOS: Physical sciences ,02 engineering and technology ,Quantum metrology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Computer Science::Emerging Technologies ,0103 physical sciences ,Quantum system ,Statistical physics ,Hardware_ARITHMETICANDLOGICSTRUCTURES ,010306 general physics ,Quantum ,Quantum Physics ,Multidisciplinary ,Quantum noise ,General Chemistry ,021001 nanoscience & nanotechnology ,Noise ,Qubit ,0210 nano-technology ,Quantum Physics (quant-ph) ,Qubits ,Coherence (physics) - Abstract
System noise identification is crucial to the engineering of robust quantum systems. Although existing quantum noise spectroscopy (QNS) protocols measure an aggregate amount of noise affecting a quantum system, they generally cannot distinguish between the underlying processes that contribute to it. Here, we propose and experimentally validate a spin-locking-based QNS protocol that exploits the multi-level energy structure of a superconducting qubit to achieve two notable advances. First, our protocol extends the spectral range of weakly anharmonic qubit spectrometers beyond the present limitations set by their lack of strong anharmonicity. Second, the additional information gained from probing the higher-excited levels enables us to identify and distinguish contributions from different underlying noise mechanisms., Comment: 23 pages, 9 figures
- Published
- 2021