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Jeudi 5 Janvier 2017 à 14h00
Amphi Holweck, Esc C
1ème etage
Josephson parametric amplifiers for a dark matter axion search
Axions are hypothetical particles that could account for the dark matter present in the universe. In a cavity haloscope such as that housed at Yale, axions may convert to photons, generating power of a few hundred yoctowatts somewhere in the 4 - 12 GHz band [1]. Detecting such a feeble signal over the noise of the electromagnetic vacuum requires state of the art microwave amplifiers, such as Josephson parametric amplifiers (JPA) [2]. In the phase insensitive mode of operation, a JPA operates close to the standard quantum limit, and has been successfully used to look for axions around 5.8 GHz [3,4]. In the phase sensitive mode, it creates a squeezed microwave state, which, upon subsequent measurement, allows the experimentalist to circumvent the standard quantum limit for one of the two signal quadratures. We propose to use this feature to greatly accelerate the search for axionic dark matter [5].
References :
[1] Shokair, T. M., et al, Int. J. Mod. Phys. A 29, 1443004 (2014).
[2] Castellanos-Beltran, M. A., et al. Nature Physics 4.12 (2008) : 929-931.
[3] Brubaker, B. M., et al, arXiv 1610.02580, (2016).
[4] Al Kenany, S., et al, arXiv 1611.07123, (2016)