Comment on “Vortices induced in a superconducting loop by asymmetric kinetic inductance and their detection in transport measurements”

The paper by G. R. Berdiyorov, M. V. Milosevic, and F. M. Peeters [Phys. Rev. B 81, 144511 (2010)] studies theoretically the dynamic properties of a superconducting loop. The authors allege that their consideration of an asymmetric loop relates to our experimental results in this field. We try to show that their theoretical results can not be used for interpreting the experimental results obtained by measuring of the quantum periodicity in the critical current, dc voltage, and resistance of superconducting loops.

Figure 1

Typical current-voltage characteristics (CVCs) of a single aluminium ring at $T<0.99T_c$. The ring with the radius $r\approx 2\mu \text{m}$, the photos of which are shown, jumps from superconducting into normal state with the resistance $R=R_n$ and $n_s=0$ when the value of the external current $|I_{\mathrm{ext}}|$ reaches the critical values $I_{c+}$ or $I_{c-}$ and retrieves superconducting state with $R=0$ and a nonzero pair density $n_s>0$ when the $|I_{\mathrm{ext}}|$ value decreases down to $I_{rs}$. The arrows along CVC indicate the direction of the $I_{\mathrm{ext}}$ change in time.