Kovacs Memory Effect with an Optically Levitated Nanoparticle Militaru, Andrei Lasanta Becerra, Antonio Rica Alarcón, Raúl Alberto This research has been supported by European Union's Horizon 2020 Research and Innovation Programme under GrantNo. 863132 (iQLev) and by the SwissNational Science Foundation through Grant No. 200021L-169319. A. L. acknowledges financial support by the FEDER/Ministerio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion, under Grants No. MTM2017-84446-C2-2-R and No. PID2020-116567GB-C22. L. L. B. acknowledges financial support by the FEDER/Ministerio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion, under Grants No. MTM2017-84446-C2-2-R and No. PID2020-112796RB-C22, the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M23), and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation). R. A. R. acknowledges financial support from FEDER/Junta de Andalucia-Consejeria de Economia y Conocimiento/Projects No. C-FQM-410UGR18 and No. P18-FR-3583. The understanding of the dynamics of nonequilibrium cooling and heating processes at the nanoscale is still an open problem. These processes can follow surprising relaxation paths due to, e.g., memory effects, which significantly alter the expected equilibration routes. The Kovacs effect can take place when a thermalization process is suddenly interrupted by a change of the bath temperature, leading to a nonmonotonic evolution of the energy of the system. Here, we demonstrate that the Kovacs effect can be observed in the thermalization of the center of mass motion of a levitated nanoparticle. The temperature is controlled during the experiment through an external source of white Gaussian noise that mimics an effective thermal bath at a temperature that can be changed faster than any relaxation time of the system.We describe our experiments in terms of the dynamics of a Brownian particle in a harmonic trap without any fitting parameter, suggesting that the Kovacs effect can appear in a large variety of systems. 2021-11-04T13:18:44Z 2021-11-04T13:18:44Z 2021-09-24 journal article Militaru, A... [et al.]. Kovacs Memory Effect with an Optically Levitated Nanoparticle. PHYSICAL REVIEW LETTERS 127, 130603 (2021). [https://doi.org/10.1103/PhysRevLett.127.130603] http://hdl.handle.net/10481/71292 10.1103/PhysRevLett.127.130603 eng info:eu-repo/grantAgreement/EC/H2020/863132 http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España American Physical Society