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Lossless on-chip microwave circulator using Josephson parametric converters

Baleegh Abdo, Archana Kamal, Michael Hatridge +3 more

Bulletin of the American Physical SocietyMar 21, 20110 citations

Performance of an on-chip superconducting circulator for quantum microwave systems

Benjamin J. Chapman, Eric I. Rosenthal, Bradley A. Moores +8 more

Bulletin of the American Physical SocietyMar 16, 20170 citations

Nonreciprocal Microwave Signal Processing with a Field-Programmable Josephson Amplifier

Florent Lecocq, Leonardo Ranzani, G. A. Peterson +4 more

The authors program a superconducting circuit $i\phantom{\rule{0}{0ex}}n$ $s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u$ to operate as a microwave circulator, or a directional amplifier. The compact lumped element can be directly integrated with other superconducting circuitry for nearly lossless routing and measurement of quantum microwave signals. This work combines advanced understanding of parametric-coupling physics with innovative design and engineering, for fundamental impact on quantum measurements plus direct technological impact on current efforts to build scalable, on-chip infrastructure for quantum computing.The authors program a superconducting circuit $i\phantom{\rule{0}{0ex}}n$ $s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u$ to operate as a microwave circulator, or a directional amplifier. The compact lumped element can be directly integrated with other superconducting circuitry for nearly lossless routing and measurement of quantum microwave signals. This work combines advanced understanding of parametric-coupling physics with innovative design and engineering, for fundamental impact on quantum measurements plus direct technological impact on current efforts to build scalable, on-chip infrastructure for quantum computing.

arXiv:1612.01438Physical Review AppliedFeb 27, 2017219 citations

Josephson Directional Amplifier for Quantum Measurement of Superconducting Circuits

Baleegh Abdo, Katrina Sliwa, Shyam Shankar +4 more

We realize a microwave quantum-limited amplifier that is directional and can therefore function without the front circulator needed in many quantum measurements. The amplification takes place in only one direction between the input and output ports. Directionality is achieved by multipump parametric amplification combined with wave interference. We have verified the device noise performances by using it to read out a superconducting qubit and observed quantum jumps. With an improved version of this device, the qubit and preamplifer could be integrated on the same chip.We realize a microwave quantum-limited amplifier that is directional and can therefore function without the front circulator needed in many quantum measurements. The amplification takes place in only one direction between the input and output ports. Directionality is achieved by multipump parametric amplification combined with wave interference. We have verified the device noise performances by using it to read out a superconducting qubit and observed quantum jumps. With an improved version of this device, the qubit and preamplifer could be integrated on the same chip.

arXiv:1311.5345Physical Review LettersApr 22, 2014105 citations

On-chip single-pump interferometric Josephson isolator for quantum measurements

Baleegh Abdo, Oblesh Jinka, Nicholas T. Bronn +2 more

Nonreciprocal microwave devices, such as circulators and isolators, are critical in high-fidelity qubit readout schemes. They unidirectionally route the readout signals and protect the qubits against noise coming from the output chain. However, cryogenic circulators and isolators are prohibitive in scalable superconducting architectures because they rely on magneto-optical effects. Here, we realize an on-chip, single-microwave-pump Josephson ISolator (JIS), formed by coupling two nondegenerate Josephson mixers in an interferometric scheme. We unravel the interplay between the orientation parity of the magnetic fluxes, biasing the mixers, and the JIS directionality. Furthermore, we build a motherboard, which integrates the JIS and other superconducting components, including a Josephson directional amplifier, into a printed circuit and use it to read out a qubit with 92% fidelity, while maintaining 75% of its T2E. Improved versions of this motherboard could replace magnetic circulators and isolators in large superconducting quantum processors.Nonreciprocal microwave devices, such as circulators and isolators, are critical in high-fidelity qubit readout schemes. They unidirectionally route the readout signals and protect the qubits against noise coming from the output chain. However, cryogenic circulators and isolators are prohibitive in scalable superconducting architectures because they rely on magneto-optical effects. Here, we realize an on-chip, single-microwave-pump Josephson ISolator (JIS), formed by coupling two nondegenerate Josephson mixers in an interferometric scheme. We unravel the interplay between the orientation parity of the magnetic fluxes, biasing the mixers, and the JIS directionality. Furthermore, we build a motherboard, which integrates the JIS and other superconducting components, including a Josephson directional amplifier, into a printed circuit and use it to read out a qubit with 92% fidelity, while maintaining 75% of its T2E. Improved versions of this motherboard could replace magnetic circulators and isolators in large superconducting quantum processors.

Jun 2, 20205 citations

Design and initial tests of a superconducting circulator for quantum microwave systems

Benjamin J. Chapman, Eric I. Rosenthal, Brad Moores +4 more

Bulletin of the American Physical SocietyMar 17, 20160 citations

On-chip integration of a superconducting microwave circulator and a Josephson parametric amplifier

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