Abstract
Two superconductors coupled by a weak link support an equilibrium Josephson electrical current that depends on the phase difference ϕ between the superconducting condensates1. Yet, when a temperature gradient is imposed across the junction, the Josephson effect manifests itself through a coherent component of the heat current that flows opposite to the thermal gradient for |ϕ| < π/2 (refs 2–4). The direction of both the Josephson charge and heat currents can be inverted by adding a π shift to ϕ. In the static electrical case, this effect has been obtained in a few systems, for example via a ferromagnetic coupling5,6 or a non-equilibrium distribution in the weak link7. These structures opened new possibilities for superconducting quantum logic6,8 and ultralow-power superconducting computers9. Here, we report the first experimental realization of a thermal Josephson junction whose phase bias can be controlled from 0 to π. This is obtained thanks to a superconducting quantum interferometer that allows full control of the direction of the coherent energy transfer through the junction10. This possibility, in conjunction with the completely superconducting nature of our system, provides temperature modulations with an unprecedented amplitude of ∼100 mK and transfer coefficients exceeding 1 K per flux quantum at 25 mK. Then, this quantum structure represents a fundamental step towards the realization of caloritronic logic components such as thermal transistors, switches and memory devices11,10. These elements, combined with heat interferometers3,4,12 and diodes13,14, would complete the thermal conversion of the most important phase-coherent electronic devices and benefit cryogenic microcircuits requiring energy management, such as quantum computing architectures and radiation sensors.
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References
Josephson, B. D. Possible new effects in superconductive tunneling. Phys. Lett. 1, 251–253 (1962).
Maki, K. & Griffin, A. Entropy transport between two superconductors by electron tunneling. Phys. Rev. Lett. 15, 921–923 (1965).
Giazotto, F. & Martínez-Pérez, M. J. The Josephson heat interferometer. Nature 492, 401–405 (2012).
Martínez-Pérez, M. J. & Giazotto, F. A quantum diffractor for thermal flux. Nat. Commun. 5, 3579 (2014).
Ryazanov, V. V. et al. Coupling of two superconductors through a ferromagnet: evidence for a π junction. Phys. Rev. Lett. 86, 2427–2430 (2001).
Gingrich, E. C. et al. Controllable 0–π Josephson junctions containing a ferromagnetic spin valve. Nat. Phys. 12, 564–567 (2016).
Baselmans, J. J. A., Morpurgo, A. F., van Wees, B. J. & Klapwijk, T. M. Reversing the direction of the supercurrent in a controllable Josephson junction. Nature 397, 43–45 (1999).
Feofanov, A. K. et al. Implementation of superconductor/ferromagnet/superconductor π-shifters in superconducting digital and quantum circuits. Nat. Phys. 6, 593–597 (2010).
Holmes, D. S., Ripple, A. L. & Manheimer, M. A. Energy-efficient superconducting computing-power budgets and requirements. IEEE Trans. Appl. Supercond. 23, 170610 (2013).
Fornieri, A., Timossi, G., Bosisio, R., Solinas, P. & Giazotto, F. Negative differential thermal conductance and heat amplification in superconducting hybrid devices. Phys. Rev. B 93, 134508 (2016).
Martínez-Pérez, M. J., Solinas, P. & Giazotto, F. Coherent caloritronics in Josephson-based nanocircuits. J. Low Temp. Phys. 175, 813–837 (2014).
Fornieri, A., Blanc, C., Bosisio, R., D'Ambrosio, S. & Giazotto, F. Nanoscale phase engineering of thermal transport with a Josephson heat modulator. Nat. Nanotech. 11, 258–262 (2016).
Martínez-Pérez, M. J., Fornieri, A. & Giazotto, F. Rectification of electronic heat current by a hybrid thermal diode. Nat. Nanotech. 10, 303–307 (2015).
Martínez-Pérez, M. J. & Giazotto, F. Efficient phase-tunable Josephson thermal rectifier. Appl. Phys. Lett. 102, 182602 (2013).
Tinkham, M . Introduction to Superconductivity (McGraw-Hill, 1996).
Guttman, G. D., Nathanson, B., Ben-Jacob, E. & Bergman, D. J. Phase-dependent thermal transport in Josephson junctions. Phys. Rev. B 55, 3849–3855 (1997).
Giazotto, F. & Martínez-Pérez, M. J. Phase-controlled superconducting heat-flux quantum modulator. Appl. Phys. Lett. 101, 102601 (2012).
Barone, A. & Paternò, G. Physics and Applications of the Josephson Effect (Wiley, 1982).
Pop, I. M. et al. Coherent suppression of electromagnetic dissipation due to superconducting quasiparticles. Nature 508, 369–372 (2014).
Giazotto, F., Heikkilä, T. T., Luukanen, A., Savin, A. M. & Pekola, J. P. Opportunities for mesoscopics in thermometry and refrigeration: physics and applications. Rev. Mod. Phys. 78, 217–274 (2006).
Tirelli, S. et al. Manipulation and generation of supercurrent in out-of-equilibrium Josephson tunnel nanojunctions. Phys. Rev. Lett. 101, 077004 (2008).
Quaranta, O., Spathis, P., Beltram, F. & Giazotto, F. Cooling electrons from 1 to 0.4 K with V-based nanorefrigerators. Appl. Phys. Lett. 98, 032501 (2011).
Clarke, J. & Braginski, A. I. (eds) The SQUID Handbook (Wiley-VCH, 2004).
Wellstood, F. C., Urbina, C. & Clarke, J. Hot-electron effects in metals. Phys. Rev. B 49, 5942–5955 (1994).
Timofeev, A. V. et al. Recombination-limited energy relaxation in a Bardeen–Cooper–Schrieffer superconductor. Phys. Rev. Lett. 102, 017003 (2009).
Timofeev, A. V., Helle, M., Meschke, M., Möttönen, M. & Pekola, J. P. Electronic refrigeration at the quantum limit. Phys. Rev. Lett. 102, 200801 (2009).
Pascal, L. M. A., Courtois, H. & Hekking, F. W. J. Circuit approach to photonic heat transport. Phys. Rev. B 83, 125113 (2011).
Meschke, M., Guichard, W. & Pekola, J. P. Single-mode heat conduction by photons. Nature 444, 187–190 (2006).
Bosisio, R., Solinas, P., Braggio, A. & Giazotto, F. Photonic heat conduction in Josephson-coupled Bardeen–Cooper–Schrieffer superconductors. Phys. Rev. B 93, 144512 (2016).
Li, N. et al. Phononics: manipulating heat flow with electronic analogs and beyond. Rev. Mod. Phys. 84, 1045–1066 (2012).
Acknowledgements
The authors acknowledge financial support from the MIUR-FIRB2013–Project Coca (grant no. RBFR1379UX), the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 615187 – COMANCHE, and the European Union (FP7/2007-2013)/REA grant agreement no. 630925 – COHEAT.
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A.F. fabricated the samples. A.F. and G.T. performed the measurements. A.F. and G.T. analysed the data and carried out the simulations with inputs from P.V., P.S. and F.G. A.F. and F.G. conceived the experiment. All authors discussed the results and their implications equally at all stages, and wrote the manuscript.
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Fornieri, A., Timossi, G., Virtanen, P. et al. 0–π phase-controllable thermal Josephson junction. Nature Nanotech 12, 425–429 (2017). https://doi.org/10.1038/nnano.2017.25
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DOI: https://doi.org/10.1038/nnano.2017.25
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