Analog information processing at the quantum limit with a Josephson ring modulator

By N. Bergeal, R Patil Vijay, V. Manucharyan, Irfan Siddiqi, Robert J. Schoelkopf, Steven M. Girvin, Michel H. Devoret. 2008

209 citations recorded by the source corpus.

Amplifiers are crucial in every experiment carrying out a very sensitive measurement. However, they always degrade the information by adding noise. Quantum mechanics puts a limit on how small this degradation can be. Theoretically, the minimum noise energy added by a phase-preserving amplifier to the signal it processes amounts at least to half a photon at the signal frequency. Here we propose a practical microwave device that can fulfil the minimal requirements to reach the quantum limit. The availability of such a device is of importance for the readout of solid-state qubits, and more generally for the measurement of very weak signals in various areas of science. We discuss how this device can be the basic building block for a variety of practical applications, such as amplification, noiseless frequency conversion, dynamic cooling and production of entangled signal pairs. The minimum noise energy that a phase-preserving amplifier adds to the signal is fundamentally limited to half a photon. A proposed parametric amplifier based on Josephson junctions should be able to reach this limit at microwave frequencies.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/4972483666d0c025f7b0a472845a0bbc2afb7971

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Artificial Intelligence

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Experimental violation of a Bell’s inequality in time with weak measurement (2010, background): “, and towards certain quantum feedback schemes: if the continuous monitoring could be carried out with a quantum-limited amplifie”
Introduction to parametric amplification of quantum signals with Josephson circuits (2016, background): “The non-degenerate parametric amplifier (case (i) of last section) can be implemented by a 3-mode, 3-port circuit employing four junctions forming the so-called Josephson ring modulator, a purely dispersive 3-wave mixer (see details in [24, 25, 26]).”
Noiseless non-reciprocity in a parametric active device (2010, methodology): “In practice, such a device can be implemented on-chip using two ring modulators based on Josephson junctions, along the lines of the recently demonstrated experiment with a Josephson parametric converte”
Colloquium: Stimulating uncertainty: Amplifying the quantum vacuum with superconducting circuits (2011, methodology): “Phase-preserving amplification with a noise level three times that of the quantum limit was demonstrated in (Bergeal et al., 2010b).”
Hardware-efficient variational quantum eigensolver for small molecules and quantum magnets (2017, background): “The reflected readout signals are amplified first by a JPC, pumped at a frequency ωPi, followed by HEMT amplifiers at 4K. 8 Qubit Q1 Q2 Q3 Q4 Q5 Q6 ω01/2π (GHz) 5.3206 5.3567 5.2926 5.2455 5.2999 5.3882 T1(µs) 24.7± 3.2 42.0± 5.1 20.4± 4.4 42.3± 5.2 44.4± 4.9 20.6± 0.8 T2(µs) 31.1± 6.1 38.7± 12.5 35”
Widely Tunable On-Chip Microwave Circulator for Superconducting Quantum Circuits (2017, methodology): “Here, “quantum” is used to mean an amplifier with added noise approximately equal to half a photon [66]—for example, a Josephson parametric amplifier [24] or a Josephson parametric converter [25].”
Microwave photonics with superconducting quantum circuits (2017, methodology): “To resolve the measured weak signal, various amplifiers, such as the Josephson bifurcation amplifier [97, 98, 102, 103], the Josephson ring amplifier [104], or parametric amplifiers [105] are used (a more extensive overview of amplifiers is given in Sec.”