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.
Low-noise and wide-bandwidth current readout at low temperatures using a superconducting-quantum-interference-device amplifier / Tran, Ngoc Thanh Mai; Okazaki, Yuma; Nakamura, Shuji; Ortolano, Massimo; Kaneko, Nobu Hisa. - In: JAPANESE JOURNAL OF APPLIED PHYSICS. PART 1, REGULAR PAPERS & SHORT NOTES. - ISSN 0021-4922. - STAMPA. - 56:4(2017), p. 04CK10. [10.7567/JJAP.56.04CK10]
Low-noise and wide-bandwidth current readout at low temperatures using a superconducting-quantum-interference-device amplifier
ORTOLANO, Massimo;
2017
Abstract
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.Pubblicazioni consigliate
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https://hdl.handle.net/11583/2671322
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