High-Tc Josephson parametric amplifier – ARPEJ

The development of high-frequency technologies in the millimeter range (30-300 GHz) opens up many perspectives in various technological fields, in particular that of communication and information processing systems. One of the key elements in the signal processing chain is the amplifier whose characteristics in terms of gain, bandwidth and noise mainly determines the performance of the chain. High electron mobility transistors (HEMT) based on indium phosphide and gallium arsenide currently offer very good performances for low noise amplification in the [1-100GHz] range when cooled to cryogenic temperatures (<10 K). They generally have high gains (> 20dB), bandwidths of one or more octaves and a large dynamic range. For the most demanding applications such as non-destructive readout of quantum bits state or for radioastronomy, Josephson Parametric Amplifiers (JPA) offer better noise performance by approaching the quantum limit. These amplifiers exploit the non-linear response of Josephson junctions or superconducting SQUIDs to transfer energy from an high amplitude pump tone to the signal to be processed. Conventional JPAs generally incorporate resonant elements, but when bandwidths of one or more octaves are required, traveling wave JPAs consisting of microwave transmission lines with multiple Josephson elements are preferable.
Parametric amplifiers are today exclusively fabricated with conventional superconducting materials such as Aluminum (Tc˜1.2K) or Niobium (Tc˜9.2K). They are operated at very low temperature in dilution refrigerators (<50mK) to suppress thermal fluctuations and generally work in a restricted frequency range [1-10GHz]. To make this technology more accessible, especially in fields of applications that do not require ultimate sensitivity (communications, security systems, space, environment, etc.), it would be very interesting to extend the operating temperature range of these amplifiers up to 30-50K, and thus limits the constraint of a very heavy cryogenics. Likewise, to follow the rise in frequency of millimeter-scale technologies, it is desirable to extend the operating frequencies up to 100 GHz and beyond, a range in which HEMT amplifiers struggle to operate.
The objective of the ARPEJ project is to harness the Josephson superconducting quantum effect to develop very low noise and low consumption amplifiers, which would establish an enabling technology for the next generation of millimeter sensors. The project aims at fabricating a Josephson traveling wave parametric amplifier made of a high critical temperature superconductors (YBa2Cu3O7) that can operate at a temperature between 30K and 50K. The design will be adapted from the recent work of the Institut Néel partner and the device will be produced using the irradiated Josephson junction technology developed for several years within the ESPCI-THALES-C2N partnership. The high frequency potential of these junctions has already been demonstrated with the realization of Josephson heterodyne mixers operating up to 400 GHz. A first demonstrator operating in the Ka band (26.5-40 GHz) used in particular for satellite communications and military radars will allow the potential of the technology to be assessed. The final goal will be to fabricate a parametric amplifier operating in the W range (75-110GHz) corresponding to one of the atmospheric transmission windows. The technologies developed in the ARPEJ project relate very directly to the fields of activity of the industrial partner THALES TRT.