We report on the development of a current amplifier for measuring small currents from mesoscopic electronic devices at low temperatures down to the milli-Kelvin range. In our setup, a superconducting quantum interference device (SQUID) located at the mixing chamber stage of the dilution refrigerator is used as the first-stage current amplifier, thereby improving the noise floor down to 8 ' 10%27A2/Hz, which is one order of magnitude as low as those obtained by the conventional methods that utilize a semiconductor-based cryogenic current amplifier. We show the configuration of this setup and demonstrate the amplification of the current generated by a quantum point contact. This approach can open a new way to examine solid-state phenomena that are elusive owing to their small current.
|Titolo:||Low-noise and wide-bandwidth current readout at low temperatures using a superconducting-quantum-interference-device amplifier|
|Data di pubblicazione:||2017|
|Digital Object Identifier (DOI):||10.7567/JJAP.56.04CK10|
|Appare nelle tipologie:||1.1 Articolo in rivista|
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