SÁNCHEZ, Raquel; MARTÍNEZ-VILCHES, David (eds.), Respectable Professionals. The Origins of the Liberal Professions in Nineteenth-Century Spain. Oxford, Peter Lang, 2021, 422 pp.

SÁNCHEZ, Raquel; MARTÍNEZ-VILCHES, David (eds.), Respectable Professionals. The Origins of the Liberal Professions in Nineteenth-Century Spain. Oxford, Peter Lang, 2021, 422 pp

SÁNCHEZ, Raquel; MARTÍNEZ-VILCHES, David (eds.), Respectable Professionals. The Origins of the Liberal Professions in Nineteenth-Century Spain. Oxford, Peter Lang, 2021, 422 pp.

SÁNCHEZ, Raquel; MARTÍNEZ-VILCHES, David (eds.), Respectable Professionals. The Origins of the Liberal Professions in Nineteenth-Century Spain. Oxford, Peter Lang, 2021, 422 pp

Supersolid formation in a dipolar condensate by roton instability

We characterize the role of roton instability in the formation of a supersolid state of an elongated dipolar condensate, following a quench of the contact interactions across the superfluid-supersolid transition, as observed in recent experiments. We perform dynamical simulations by means of the extended Gross-Pitaevskii equation including quantum corrections, for different final values of the s−wave scattering length. The corresponding excitation spectrum is computed using an effective one-dimensional description, which provides a reasonably accurate prediction for the growth rate of the most unstable mode observed in the simulations. To analyze the behavior of the system, we employ the inverse participation ratio, which conveniently characterizes the different degree of localization in the superfluid and supersolid phases. By means of a suitable effective ansatz for the density, we derive a simple yet effective expression for the formation time of the supersolid. This expression provides valuable insights regarding its scaling behavior with respect to the s-wave scattering length.This work was supported by Grant No. PID2021-126273NB-I00 funded by MCIN/AEI/10.13039/5011000 11033 by “ERDF A way of making Europe,” by the Basque Government through Grant No. IT1470-22, and by the European Research Council through the Advanced Grant “Supersolids” (Grant No. 101055319)

Crossing the superfluid-supersolid transition of an elongated dipolar condensate

We provide a theoretical characterization of the dynamical crossing of the superfluid-supersolid phase transition for a dipolar condensate confined in an elongated trap, as observed in the recent experiment by G. Biagioni et al. [Phys. Rev. X 12, 021019 (2022)]. By means of the extended Gross-Pitaevskii theory, which includes the Lee-Huang-Yang quantum fluctuation correction, we first analyze the ground state configurations of the system as a function of the interparticle scattering length, for both trap configurations employed in the experiment. Then, we discuss the effects of the ramp velocity, by which the scattering length is tuned across the transition, on the collective excitations of the system in both the superfluid and supersolid phases. We find that, when the transverse confinement is sufficiently strong and the transition has a smooth (continuous) character, the system essentially displays a (quasi) 1D behavior, its excitation dynamics being dominated by the axial breathing modes. Instead, for shallower transverse trapping, when the transition becomes discontinuous, the collective excitations of the supersolid display a coupling with the transverse modes, signalling the onset of a dimensional crossover.Comment: 9 pages, 8 figure

Bi oszilagailu harmonikodun eredu minimalista baten bidezko bero-errektifikazioa

We study heat rectification using a minimalistic model of two different atoms trapped in harmonic potentials, where the atoms are subjected to effective Lan-gevin baths created by the Doppler cooling, while they interact by linear forces. We obtain analytical expressions for the steady state. If the exchange of baths is done changing temperature and friction coefficients at the same time an asymmetry of heat current is found. We also search for the highest asymmetry in the parameter space of the system.; Bero-errektifikazioa aztertzen dugu harrapatutako bi atomo ezberdi-nez osatutako modelo minimalista baten bidez. Atomoek indar linealak jasaten dituzte laserren bidez sorturiko Langevin bainu efektiboekin kontaktuan, Doppler efektuaren bidez sortuak. Egoera egonkorreko korronteen adierazpen analitikoak lortzen ditugu. Sistema lineal honetan bero-korronte asimetrikoa lortzen da bainuen tenperatura eta bainuek sistemarekiko duten akoplamendua aldi berean trukatzen badira. Modelo honen parametro- espazioa ere aztertzen dugu bero-korronte asimetria maximizatzeko

Supersolid formation time shortcut and excitation reduction by manipulating the dynamical instability

Supersolids are a phase of matter exhibiting both superfluidity and a periodic density modulation typical of crystals. When formed via quantum phase transition from a superfluid, they require a formation time before their density pattern develops. Along this paper some protocols/schemes are proposed for experimental applications, building on earlier descriptions of the role roton instability plays in the supersolid formation process and the associated formation time. In particular, the Parachutejump scheme sought to lessen the excitation produced when crossing the phase transition, and the Bang-Bang method sought to shorten the formation time. As a case study of the impact that mechanical fluctuations (noise) can have on the phase transition when conducting an experiment, the impact of a mechanical kick before the transition is also investigated. The proposed schemes are able to fulfill their objectives successfully as both the shortening of the formation process and the reduction of excitation are achieved within the framework of extended Gross Pitaevskii theory

Jorge Vilches, La Primera República Española (1873-1874). De la utopía al caos, Madrid, Espasa, 2023

Las efemérides son siempre un buen momento para realizar una revisión historiográfica sobre el periodo objeto de recuerdo. Si a eso se le suma el resultado de muchos años de sólida investigación con la incorporación y el tratamiento de diversas fuentes primarias, principalmente archivísticas e inéditas, nos sale una obra como la que aquí se reseñ