{'fraction_non_alphanumeric': 0.03783783783783784, 'fraction_numerical': 0.02972972972972973, 'mean_word_length': 5.226890756302521, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Quantum limited heterodyne detection in superconducting non‐linear transmission lines at sub‐millimeter wavelengths

A non‐linear superconducting transmission line has been successfully employed in heterodyne detection of sub‐millimeter waves. In our experiments an Nb/Al/AlOx/Nb tunnel junction, measuring 0.15×40 μm, with a critical current density of about 2500 A/cm2 is used as a distributed mixer element. We have demonstrated that quantum limited sensitivity can be achieved with this type of device. At 460 GHz, a Y‐factor of 2.5 has been recorded, corresponding to a double‐side‐band receiver noise temperature of 80 K. The double‐side‐band conversion loss is about 1 dB and the mixer noise temperature is estimated to be 18(±10) K.