Coulomb Blockade and Bloch Oscillations in Superconducting Ti Nanowires

Physical Review Letters. 2012. Vol. 109. No. 18. P. 187001–187005.

Arutyunov K., Lehtinen J. S., Zakharov K.

Quantum fluctuations in quasi-one-dimensional superconducting channels leading to spontaneous
changes of the phase of the order parameter by 2
, alternatively called quantum phase slips (QPS),
manifest themselves as the finite resistance well below the critical temperature of thin superconducting
nanowires and the suppression of persistent currents in tiny superconducting nanorings. Here we report the
experimental evidence that in a current-biased superconducting nanowire the same QPS process is
responsible for the insulating state—the Coulomb blockade. When exposed to rf radiation, the internal
Bloch oscillations can be synchronized with the external rf drive leading to formation of quantized current
steps on the I-V characteristic. The effects originate from the fundamental quantum duality of a Josephson
junction and a superconducting nanowire governed by QPS—the QPS junction

Keywords: метрология, нанотехнологии, nanotechnology, mesoscopic superconductors, мезоскопические сверхпроводники, quantum phenomena, квантовые явления, metrology