arXiv subjects

Mauricio Trujillo Martinez

Publications and source records attributed to Mauricio Trujillo Martinez.

2 recordsLinked to original sources

arXiv2013

Tuning the Ultrafast Spin Dynamics in Carrier-Density-Controlled Ferromagnets

Ultrafast strengthening or quenching of the ferromagnetic order of semiconducting Eu1-xGdxO was achieved by resonant photoexcitation. The modification of the magnetic order is established within 3 ps as revealed by optical second harmonic generation. A theoretical analysis shows that the response is determined by the interplay of chemically and optically generated carriers in a nonequilibrium scenario beyond the three-temperature model. General criteria for the design of spintronics materials with tunable ultrafast spin dynamics are given.

cond-mat.str-el↗

arXiv2009

Nonequilibrium Josephson oscillations in Bose-Einstein condensates without dissipation

We perform a detailed field theoretical study of nonequilibrium Josephson oscillations between interacting Bose-Einstein condensates confined in a finite-size double-well trap. We find that the Josephson junction can sustain multiple undamped Josephson oscillations up to a characteristic time scale $τ_c$ without quasipartcles being excited in the system. This may explain recent related experiments. At larger times the dynamics of the junction is governed by fast Rabi oscillations between the descrete quasiparticle levels. We predict that a selftrapped BEC state will be destroyed by these Rabi oscillations.

cond-mat.quant-gas↗