The fundamental phenomenon of Bose–Einstein condensation has been observed in different systems of real particles and quasiparticles. The condensation of real particles is achieved through a major reduction in temperature, while for quasiparticles, a mechanism of external injection of bosons by irradiation is required. Here, we present a new and universal approach to enable Bose–Einstein condensation of quasiparticles and to corroborate it experimentally by using magnons as the Bose-particle model system. The critical point to this approach is the introduction of a disequilibrium of magnons with the phonon bath. After heating to an elevated temperature, a sudden decrease in the temperature of the phonons, which is approximately instant on the time scales of the magnon system, results in a large excess of incoherent magnons. The consequent spectral redistribution of these magnons triggers the Bose–Einstein condensation.
Subscribe to Journal
Get full journal access for 1 year
only $15.58 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Anderson, M. H., Ensher, J. R., Matthews, M. R., Wieman, C. E. & Cornell, E. A. Observation of Bose–Einstein condensation in a dilute atomic vapor. Science 269, 198–201 (1995).
Santra, B. et al. Measuring finite-range phase coherence in an optical lattice using Talbot interferometry. Nat. Commun. 8, 15601 (2017).
Kasprzak, J. et al. Bose–Einstein condensation of exciton polaritons. Nature 443, 409–414 (2006).
Lerario, G. et al. Room-temperature superfluidity in a polariton condensate. Nat. Phys. 13, 837–841 (2017).
Klaers, J., Schmitt, J., Vewinger, F. & Weitz, M. Bose–Einstein condensation of photons in an optical microcavity. Nature 468, 545–548 (2010).
Damm, T. et al. Calorimetry of a Bose–Einstein-condensed photon gas. Nat. Commun. 7, 11340 (2016).
Nikuni, T., Oshikawa, M., Oosawa, A. & Tanaka, H. Bose–Einstein condensation of dilute magnons in TlCuCl3. Phys. Rev. Lett. 84, 5868–5871 (2000).
Yin, L., Xia, J. S., Zapf, V. S., Sullivan, N. S. & Paduan-Filho, A. Direct measurement of the Bose-Einstein condensation universality class in NiCl2-4SC(NH2)2 at ultralow temperatures. Phys. Rev. Lett. 101, 187205 (2008).
Giamarchi, T., Rüegg, C. & Tchernyshyov, O. Bose-Einstein condensation in magnetic insulators. Nat. Phys. 4, 198–204 (2008).
Borovik-Romanov, A. S., Bunkov, Yu. M., Dmitriev, V. V. & Mukharskiǐ, Yu. M. Long-lived induction signal in superfluid 3He-B. JETP Lett. 40, 1033–1037 (1984).
Bunkov, Yu. M. & Volovik, G. E. Magnon condensation into a q ball in 3He-B. Phys. Rev. Lett. 98, 265302 (2007).
Demokritov, S. O. et al. Bose–Einstein condensation of quasi-equilibrium magnons at room temperature under pumping. Nature 443, 430–433 (2006).
Rezende, S. M. Theory of coherence in Bose-Einstein condensation phenomena in a microwave-driven interacting magnon gas. Phys. Rev. B 79, 174411 (2009).
Serga, A. A. et al. Bose–Einstein condensation in an ultra-hot gas of pumped magnons. Nat. Commun. 5, 3452 (2014).
Bozhko, D. A. et al. Supercurrent in a room temperature Bose–Einstein magnon condensate. Nat. Phys. 12, 1057–1062 (2016).
Brächer, T., Pirro, P. & Hillebrands, B. Parallel pumping for magnon spintronics: amplification and manipulation of magnon spin currents on the micron-scale. Phys. Rep. 699, 1–34 (2017).
Safranski, C. et al. Spin caloritronic nano-oscillator. Nat. Commun. 8, 117 (2017).
Gurevich, A. G. & Melkov, G. A. Magnetization Oscillations and Waves (CRC, 1996).
Hüser, J. Kinetic Theory of Magnon Bose-Einstein Condensation. PhD thesis, Westfälische Wilhelms-Universität Münster (2016).
Dubs, C. et al. Sub-micrometer yttrium iron garnet LPE films with low ferromagnetic resonance losses. J. Phys. D 50, 204005 (2017).
Sebastian, T., Schultheiss, K., Obry, B., Hillebrands, B. & Schultheiss, H. Micro-focused Brillouin light scattering: imaging spin waves at the nanoscale. Front. Phys. 3, 35 (2015).
Cherepanov, V., Kolokolov, I. & L’vov, V. The saga of YIG. Phys. Rep. 229, 81–144 (1993).
Olsson, K. S. et al. Temperature-dependent Brillouin light scattering spectra of magnons in yttrium iron garnet and permalloy. Phys. Rev. B 96, 024448 (2017).
Bauer, G. E. W., Saitoh, E. & van Wees, B. J. Spin caloritronics. Nat. Mater. 11, 391–399 (2012).
Bender, S. A. & Tserkovnyak, Y. Thermally driven spin torques in layered magnetic insulators. Phys. Rev. B 93, 064418 (2016).
Tserkovnyak, Y., Bender, S. A., Duine, R. A. & Flebus, B. Bose-Einstein condensation of magnons pumped by the bulk spin Seebeck effect. Phys. Rev. B 93, 100402 (2016).
Uchida, K., Kikkawa, T., Miura, A., Shiomi, J. & Saitoh, E. Quantitative temperature dependence of longitudinal spin Seebeck effect at high temperatures. Phys. Rev. X 4, 041023 (2014).
Demidov, V. E. et al. Magnetization oscillations and waves driven by pure spin currents. Phys. Rep. 673, 1–31 (2017).
Chumak, A. V., Vasyuchka, V. I., Serga, A. A. & Hillebrands, B. Magnon spintronics. Nat. Phys. 11, 453–461 (2015).
Cornelissen, L. J., Liu, J., Duine, R. A., Ben Youssef, J. & van Wees, B. J. Long-distance transport of magnon spin information in a magnetic insulator at room temperature. Nat. Phys. 11, 1022–1026 (2015).
Kittel, C. Introduction to Solid State Physics (Wiley, 2005).
Stancil, D. D. & Prabhakar, A. Spin Waves: Theory and Applications (Springer, 2009).
Jungfleisch, M. B., Lauer, V., Neb, R., Chumak, A. V. & Hillebrands, B. Improvement of the yttrium iron garnet/platinum interface for spin pumping-based applications. Appl. Phys. Lett. 103, 022411 (2013).
Pirro, P. et al. Spin-wave excitation and propagation in microstructured waveguides of yttrium iron garnet/Pt bilayers. Appl. Phys. Lett. 104, 012402 (2014).
Snoke, D. Coherent questions. Nature 443, 403–404 (2006).
Nowik-Boltyk, P., Dzyapko, O., Demidov, V. E., Berloff, N. G. & Demokritov, S. O. Spatially non-uniform ground state and quantized vortices in a two-component Bose-Einstein condensate of magnons. Sci. Rep. 2, 482 (2012).
Bozhko, D. A. et al. Bogoliubov waves and distant transport of magnon condensate at room temperature. Nat. Commun. 10, 2460 (2019).
Snoke, D. Polariton condensates: a feature rather than a bug. Nat. Phys. 4, 673–673 (2008).
Eisenstein, J. P. & MacDonald, A. H. Bose–Einstein condensation of excitons in bilayer electron systems. Nature 432, 691–694 (2004).
This research was funded by ERC Starting Grant 678309 MagnonCircuits and ERC Advanced Grant 694709 Super-Magnonics, as well as by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) TRR 173—268565370 and Project DU 1427/2-1, by grants no. EFMA-1641989 and no. ECCS-1708982 from the National Science Foundation of the United States, and by the U.S. AFOSR under the MURI grant # FA9550-19-1-0307.
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
The table shows the parameters according to the developed quasi-analytical theoretical model for two different experimentally investigated strips.
a, Temperature across the layers at the end of a 120-ns-long heating pulse simulated with COMSOL (corresponding to the experiment shown in Fig. 2b in the main manuscript). b, Temperature (red curve, left axis) and temperature gradient (black curve, right axis) as a function of time simulated with COMSOL (corresponding to the experiment shown in Fig. 2b in the main manuscript).
a, Time resolved BLS spectrum for the case when a 50-ns-long pulse is applied b, Integrated BLS intensity over the frequency range shown in a.
a, BLS spectrum as a function of time. The BLS signal (colour-coded, log scale) is proportional to the density of magnons. FM indicates the fundamental mode, EM – the edge mode, and 1st M – the first thickness mode. The vertical dashed lines indicate the start and the end of the pulse (τP = 150 ns, U = 0.9 V). The external field was parallel to the short axis of the strip (B||y). c, BLS spectrum as a function of time for the case when the external magnetic field is parallel to long axis of the strip (B||x), (τP = 120 ns, U = 0.9 V). b,d, Normalized magnon intensity integrated from 4.95 GHz to 8.1 GHz as a function of time for the cases in a,c. The insets show the sample and measurement geometry.
About this article
Cite this article
Schneider, M., Brächer, T., Breitbach, D. et al. Bose–Einstein condensation of quasiparticles by rapid cooling. Nat. Nanotechnol. 15, 457–461 (2020). https://doi.org/10.1038/s41565-020-0671-z
Physical Review Research (2020)
Nano Letters (2020)