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.

arXiv commentTo be published in Physical Review B, Rapid Communications

References in corpus (6)

• Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications
• Non-Quantized Penetration of Magnetic Field in the Vortex State of Superconductors
• Geometrical destruction of the global phase coherence in ultrathin superconducting cylinders
• Attojoule calorimetry of mesoscopic superconducting loops
• Multiple flux jumps and irreversible behavior of thin Al superconducting rings
• Possible observation of phase separation near a quantum phase transition in doubly connected ultrathin superconducting cylinders of aluminum

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• New sensor for thermodynamic measurement of magnetization reversal in magnetic nanomaterials
• Fluctuations in a mesoscopic superconducting ring: resonant behavior of conductivity and specific heat in two mode critical regime
• Fine frequency shift of sigle vortex entrance and exit in superconducting loops