Thermal signatures of Little-Parks effect in the heat capacity of mesoscopic superconducting rings

Abstract

We present the first measurements of thermal signatures of the Little-Parks effect using a highly sensitive nanocalorimeter. Small variations of the heat capacity $C\_p$ of 2.5 millions of non interacting micrometer-sized superconducting rings threaded by a magnetic flux $\Phi$ have been measured by attojoule calorimetry. This non-invasive method allows the measurement of thermodynamic properties -- and hence the probing of the energy levels -- of nanosystems without perturbing them electrically. It is observed that $C\_p$ is strongly influenced by the fluxoid quantization (Little-Parks effect) near the critical temperature $T\_c$. The jump of $C\_p$ at the superconducting phase transition is an oscillating function of $\Phi$ with a period $\Phi \_0=h/2e$, the magnetic flux quantum, which is in agreement with the Ginzburg-Landau theory of superconductivity.

To be published in Physical Review B, Rapid Communications

References in corpus (1)

• Attojoule calorimetry of mesoscopic superconducting loops

Cited by in corpus (3)

• Topology effects on the heat capacity of mesoscopic superconducting disks
• Accessing topological order in fractionalized liquids with gapped edges
• Fine frequency shift of sigle vortex entrance and exit in superconducting loops