Control and readout of a superconducting artificial atom

We demonstrate control and readout of a superconducting artificial atom based on a transmon qubit using a compact lumped-element resonator. The resonator consists of a parallel-plate capacitor with a wire geometric inductor. The footprint of the resonators is about 200 × 200 μm2, which is similar to the standard transmon size and one or two orders of magnitude more compact in the occupied area compared to coplanar waveguide resonators. We observe coherent Rabi oscillations and obtain time-domain properties of the transmon. The work opens a door to miniaturize essential components of superconducting circuits and to further scale up quantum systems with superconducting transmons.We demonstrate control and readout of a superconducting artificial atom based on a transmon qubit using a compact lumped-element resonator. The resonator consists of a parallel-plate capacitor with a wire geometric inductor. The footprint of the resonators is about 200 × 200 μm2, which is similar to the standard transmon size and one or two orders of magnitude more compact in the occupied area compared to coplanar waveguide resonators. We observe coherent Rabi oscillations and obtain time-domain properties of the transmon. The work opens a door to miniaturize essential components of superconducting circuits and to further scale up quantum systems with superconducting transmons.

arXiv:2312.15753Applied Physics LettersMar 4, 20243 citations

Large-amplitude driving of a superconducting artificial atom

William D. Oliver, Sergio O. Valenzuela

arXiv:0906.0185Quantum Information ProcessingMar 11, 200948 citations

Progress in superconducting qubits from the perspective of coherence and readout

Youpeng Zhong, Chunyan Li, Haohua Wang +1 more

Superconducting qubits are Josephson junction-based circuits that exhibit macroscopic quantum behavior and can be manipulated as artificial atoms. Benefiting from the well-developed technology of microfabrication and microwave engineering, superconducting qubits have great advantages in design flexibility, controllability, and scalability. Over the past decade, there has been rapid progress in the field, which greatly improved our understanding of qubit decoherence and circuit optimization. The single-qubit coherence time has been steadily raised to the order of 10 to 100 μs, allowing for the demonstration of high-fidelity gate operations and measurement-based feedback control. Here we review recent progress in the coherence and readout of superconducting qubits.Superconducting qubits are Josephson junction-based circuits that exhibit macroscopic quantum behavior and can be manipulated as artificial atoms. Benefiting from the well-developed technology of microfabrication and microwave engineering, superconducting qubits have great advantages in design flexibility, controllability, and scalability. Over the past decade, there has been rapid progress in the field, which greatly improved our understanding of qubit decoherence and circuit optimization. The single-qubit coherence time has been steadily raised to the order of 10 to 100 μs, allowing for the demonstration of high-fidelity gate operations and measurement-based feedback control. Here we review recent progress in the coherence and readout of superconducting qubits.

Chinese Physics BNov 1, 20137 citations

Electron shelving of a superconducting artificial atom

Yen‐Hsiang Lin, Nathanaël Cottet, Haonan Xiong +2 more

Bulletin of the American Physical SocietyMar 17, 20210 citations

Minimizing the Discrimination Time for Quantum States of an Artificial Atom

I. Takmakov, P. Winkel, F. Foroughi +9 more

Fast discrimination between quantum states of superconducting artificial atoms is an important ingredient for quantum information processing. In circuit quantum electrodynamics, increasing the signal-field amplitude in the readout resonator, dispersively coupled to the artificial atom, improves the signal-to-noise ratio and increases the measurement strength. Here, we employ this effect over 2 orders of magnitude in readout power, made possible by the unique combination of a dimer-Josephson-junction-array amplifier with a large dynamic range and the fact that the readout of our granular aluminum fluxonium artificial atom remains quantum nondemolition (QND) at relatively large photon numbers in the readout resonator, up to $\overline{n}=110$ . Using Bayesian inference, this allows us to detect quantum jumps faster than the readout-resonator response time $2/\ensuremath{\kappa}$, where $\ensuremath{\kappa}$ is the bandwidth of the readout resonator.Fast discrimination between quantum states of superconducting artificial atoms is an important ingredient for quantum information processing. In circuit quantum electrodynamics, increasing the signal-field amplitude in the readout resonator, dispersively coupled to the artificial atom, improves the signal-to-noise ratio and increases the measurement strength. Here, we employ this effect over 2 orders of magnitude in readout power, made possible by the unique combination of a dimer-Josephson-junction-array amplifier with a large dynamic range and the fact that the readout of our granular aluminum fluxonium artificial atom remains quantum nondemolition (QND) at relatively large photon numbers in the readout resonator, up to $\overline{n}=110$. Using Bayesian inference, this allows us to detect quantum jumps faster than the readout-resonator response time $2/\ensuremath{\kappa}$, where $\ensuremath{\kappa}$ is the bandwidth of the readout resonator.

arXiv:2011.08687Physical Review AppliedJun 11, 20219 citations

\overline{n}=110

. Using Bayesian inference, this allows us to detect quantum jumps faster than the readout-resonator response time $2/\ensuremath{\kappa}$, where $\ensuremath{\kappa}$ is the bandwidth of the readout resonator.