ИСТИНА

Using of solitons for information receiving and processing can be very attractive due to their inherent particle-like stability joint with a wave nature. In superconducting electronic devices (e.g. all-digital-RF receiver systems [1], read-out systems for superconducting single photon detectors [2]) based on Josephson junctions, magnetic flux quantum vortices representing data bits are solitons, also called fluxons. In ballistic detectors that are widely used for mesoscopic quantum measurements, a measured system controls a transport of solitons via Josephson transmission (JTLs) lines by creating a scattering potential [3]. The detector scheme can be organized in an interferometer manner. We examine the numerical and analytical approaches for calculation of the soliton scattering at point-like successive inhomogeneities of the driving force in a presence of thermal fluctuations. Considering the scattering as a measurement tool, we argue that the accelerated soliton propagation leads to an enhancement of the signal-to-noise ratio of the detector scheme due to a relativistic dependence of a soliton mass on its velocity. Ballistic Josephson vortex interferometer scheme. G box represents a fluxon generator, Q box - a qubit and C box - a comparator. b) The detector scheme in which the coupling loop is connected symmetrically to the both JTLs. We propose an approach to symmetrize the detector scheme and explore arising advantages in the signal-to-noise ratio (SNR) and in the back-action on a measured object (see Fig. 1b). We show that symmetrization of the scheme leads to significant SNR increase due to the involvement of the both fluxons in the scattering events and effective increase of the scattering potential amplitude. At the same time, the back-action is drastically reduced because of differential origin of the backaction flux. The SNR estimation for the both cases of utilization the continuous and the discrete JTLs, for experimentally relevant parameters, is well above 100. This opens the opportunity of using the considered detector in practical applications including implementation of a unified interface circuit on the basis of RSFQ digital cells for linking the room temperature electronics and it quantum superconducting counterparts. [1] D. Gupta et al., IEEE Trans. Appl. Supercond. 21, 1EB01 (2011). [2] H. Terai, T. Yamashita, S. Miki, K. Makise, and Z. Wang, Opt. Express 20(18), 20115 (2012). [3] K.G. Fedorov, A.V. Shcherbakova, R. Schlafer, and A.V. Ustinov, Appl. Phys. Lett. 102, 132602 (2013).