Josephson junction microwave amplifier in self-organized noise compression mode

Lähteenmäki, Pasi; Vesterinen, Visa; Hassel, Juha; Seppä, Heikki; Hakonen, Pertti

doi:10.1038/srep00276

Cited by 13 publications

(31 citation statements)

References 26 publications

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“…As aforementioned, the origin of the unusual MR of β-Ag 2 Te is still under debate, which may originate from the bulk effect or surface effect 28 29 30 31 32 . To distinguish the bulk from the surface effect, high quality samples with tunable Fermi level are indispensable.…”

Section: Resultsmentioning

confidence: 99%

“…However, most of the TI materials show very small surface contribution due to defect-induced large bulk contribution and therefore electric field tunability cannot be realized. On the other hand, very few TIs that manifest electric field ambipolar effect such as Bi 2-x Sb x Te 3-y Se y 27 28 29 and thin Bi 2 Se 3 flakes 21 25 , show low mobility. On this basis, it is important to identify new TIs that show large gate electric field tunability and high surface mobility for the application of future TI based spintronic devices.…”

mentioning

confidence: 99%

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Gate-tuned quantum oscillations of topological surface states in β-Ag2Te

Sulaev

Zhu

Teo

et al. 2015

Sci Rep

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We report the strong experimental evidence of the existence of topological surface states with large electric field tunability and mobility in β-Ag2Te. Pronounced 2D Shubnikov-de Haas oscillations have been observed in β-Ag2Te nanoplates. A Berry phase is determined to be near π using the Landau level fan diagram for a relatively wide nanoplate while the largest electric field ambipolar effect in topological insulator so far (~2500%) is observed in a narrow nanoplate. The π Berry phase and the evolution of quantum oscillations with gate voltage (Vg) in the nanoplates strongly indicate the presence of topological surface states in β-Ag2Te. Moreover, the mobility of the narrow Ag2Te nanoplate is about several thousand cm2s−1V−1. Our results suggest that β-Ag2Te has the potential to become an important material in the investigation of topological insulators.

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Gate-tuned quantum oscillations of topological surface states in β-Ag2Te

Sulaev

Zhu

Teo

et al. 2015

Sci Rep

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“…Such amplifiers are bound by the standard quantum limit (SQL), which states that at high gain at least half an energy quantum of noise is added to the input signal [8]. This limit has been approached with Josephson parametric amplifiers [9][10][11][12][13][14], however, such amplifiers are limited to relatively weak input signals. Optomechanical amplifiers or detectors, utilizing the interaction between electromagnetic waves and a mechanical resonator inside a cavity [15], have been demonstrated in the microwave and optical regime [16][17][18][19], but existing techniques suffer from a limited gain and bandwidth as well as noise levels well above the SQL.…”

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confidence: 99%

Low-Noise Amplification and Frequency Conversion with a Multiport Microwave Optomechanical Device

et al. 2016

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High-gain amplifiers of electromagnetic signals operating near the quantum limit are crucial for quantum information systems and ultrasensitive quantum measurements. However, the existing techniques have a limited gain-bandwidth product and only operate with weak input signals. Here we demonstrate a two-port optomechanical scheme for amplification and routing of microwave signals, a system that simultaneously performs high-gain amplification and frequency conversion in the quantum regime. Our amplifier, implemented in a two-cavity microwave optomechanical device, shows 41 dB of gain and has a high dynamic range, handling input signals up to 10 13 photons per second, three orders of magnitude more than corresponding Josephson parametric amplifiers. We show that although the active medium, the mechanical resonator, is at a high temperature far from the quantum limit, only 4.6 quanta of noise is added to the input signal. Our method can be readily applied to a wide variety of optomechanical systems, including hybrid optical-microwave systems, creating a universal hub for signals at the quantum level. arXiv:1602.05779v1 [cond-mat.mes-hall]

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“…In earlier work [30], a one-port device based on this principle has been operated as a reflection amplifier at 2.8 GHz.…”

Section: Finite-voltage Resonancesmentioning

confidence: 99%

Dispersive Thermometry with a Josephson Junction Coupled to a Resonator

Saira¹,

Zgirski

Viisanen³

et al. 2016

Phys. Rev. Applied

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We embed a small Josephson junction in a microwave resonator that allows simultaneous dc biasing and dispersive readout. Thermal fluctuations drive the junction into phase diffusion and induce a temperaturedependent shift in the resonance frequency. By sensing the thermal noise of a remote resistor in this manner, we demonstrate primary thermometry in the range of 300 mK to below 100 mK, and highbandwidth (7.5 MHz) operation with a noise-equivalent temperature of better than 10 μK= ffiffiffiffiffiffi Hz p . At a finite bias voltage close to a Fiske resonance, amplification of the microwave probe signal is observed. We develop an accurate theoretical model of our device based on the theory of dynamical Coulomb blockade.

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Josephson junction microwave amplifier in self-organized noise compression mode

Cited by 13 publications

References 26 publications

Gate-tuned quantum oscillations of topological surface states in β-Ag2Te

Gate-tuned quantum oscillations of topological surface states in β-Ag2Te

Low-Noise Amplification and Frequency Conversion with a Multiport Microwave Optomechanical Device

Dispersive Thermometry with a Josephson Junction Coupled to a Resonator

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