aqora

Quickly Tunable Refrigerator for Superconducting Quantum Circuits

Kuan Yen Tan, Shumpei Masuda, Jan Goetz +16 more

Bulletin of the American Physical SocietyMar 6, 20180 citations

Fast Unconditional Initialization for Superconducting Qubit Using Quantum-Circuit Refrigerator

Teruaki Yoshioka

Mar 18, 20240 citations

Quickly Tunable Electromagnetic Environment for Superconducting Quantum Circuits

Vasilii Sevriuk, Kuan Yen Tan, Matti Silveri +16 more

Bulletin of the American Physical SocietyMar 6, 20190 citations

Quantum-circuit refrigeration of a superconducting microwave resonator well below a single quantum

Arto Viitanen, Timm Mörstedt, Wallace S. Teixeira +4 more

We experimentally demonstrate a recently proposed single-junction quantum-circuit refrigerator (QCR) as an tunable low-temperature environment for a superconducting 4.7 GHz resonator. With the help of a transmon qubit, we measure the populations of the different resonator Fock states, thus providing reliable access to the temperature of the engineered electromagnetic environment and its effect on the resonator. We demonstrate coherent and thermal resonator states and that the on-demand dissipation provided by the QCR can drive these to a small fraction of a photon on average, even if starting above 1 K. We observe that the QCR can be operated either with a dc bias voltage or a gigahertz rf drive, or a combination of these. The bandwidth of the rf drive is not limited by the circuit itself and consequently, we show that 2.9 GHz continuous and 10 ns pulsed drives lead to identical desired refrigeration of the resonator. These observations answer to the shortcomings of previous works where the Fock states were not resolvable and the QCR exhibited slow charging dynamics. Thus, this work introduces a versatile tool to study open quantum systems, quantum thermodynamics, and to quickly reset superconducting qubits. Published by the American Physical Society 2024We experimentally demonstrate a recently proposed single-junction quantum-circuit refrigerator (QCR) as an tunable low-temperature environment for a superconducting 4.7 GHz resonator. With the help of a transmon qubit, we measure the populations of the different resonator Fock states, thus providing reliable access to the temperature of the engineered electromagnetic environment and its effect on the resonator. We demonstrate coherent and thermal resonator states and that the on-demand dissipation provided by the QCR can drive these to a small fraction of a photon on average, even if starting above 1 K. We observe that the QCR can be operated either with a dc bias voltage or a gigahertz rf drive, or a combination of these. The bandwidth of the rf drive is not limited by the circuit itself and consequently, we show that 2.9 GHz continuous and 10 ns pulsed drives lead to identical desired refrigeration of the resonator. These observations answer to the shortcomings of previous works where the Fock states were not resolvable and the QCR exhibited slow charging dynamics. Thus, this work introduces a versatile tool to study open quantum systems, quantum thermodynamics, and to quickly reset superconducting qubits. Published by the American Physical Society 2024

arXiv:2308.00397Physical Review ResearchJun 10, 20249 citations

In-situ tunable environment for superconducting qubits

Jan Goetz, Matti Silveri, Matti Partanen +8 more

Bulletin of the American Physical SocietyJan 1, 20180 citations

Tunable refrigerator for nonlinear quantum electric circuits

Hao Hsu, Matti Silveri, András Gunyhó +3 more

The emerging quantum technological applications call for fast and accurate initialization of the corresponding devices to low-entropy quantum states. To this end, we theoretically study a recently demonstrated quantum-circuit refrigerator in the case of nonlinear quantum electric circuits such as superconducting qubits. The maximum refrigeration rate of transmon and flux qubits is observed to be roughly an order of magnitude higher than that of usual linear resonators, increasing flexibility in the design. We find that for typical experimental parameters, the refrigerator is suitable for resetting different qubit types to fidelities above 99.99% in a few or a few tens of nanoseconds depending on the scenario. Thus the refrigerator appears to be a promising tool for quantum technology and for detailed studies of open quantum systems.The emerging quantum technological applications call for fast and accurate initialization of the corresponding devices to low-entropy quantum states. To this end, we theoretically study a recently demonstrated quantum-circuit refrigerator in the case of nonlinear quantum electric circuits such as superconducting qubits. The maximum refrigeration rate of transmon and flux qubits is observed to be roughly an order of magnitude higher than that of usual linear resonators, increasing flexibility in the design. We find that for typical experimental parameters, the refrigerator is suitable for resetting different qubit types to fidelities above 99.99% in a few or a few tens of nanoseconds depending on the scenario. Thus the refrigerator appears to be a promising tool for quantum technology and for detailed studies of open quantum systems.

arXiv:2002.06867Physical review. B./Physical review. BJun 11, 202021 citations

Quickly tunable refrigerator for superconducting qubits

Related papers

Quickly tunable refrigerator for superconducting qubits

Related papers