On-demand generation of higher-order Fock states in quantum-dot--cavity systems

The on-demand preparation of higher-order Fock states is of fundamental importance in quantum information sciences. We propose and compare different protocols to generate higher-order Fock states in solid state quantum-dot--cavity systems. The protocols make use of a series of laser pulses to excite the quantum dot exciton and off-resonant pulses to control the detuning between dot and cavity. Our theoretical studies include dot and cavity loss processes as well as the pure-dephasing type coupling to longitudinal acoustic phonons in a numerically complete fashion. By going beyond the two-level approximation for quantum dots, we study the impact of a finite exchange splitting, the impact of a higher energetic exciton state, and an excitation with linearly polarized laser pulses leading to detrimental occupations of the biexciton state. We predict that under realistic conditions, a protocol which keeps the cavity at resonance with the quantum dot until the desired target state is reached is able to deliver fidelities to the Fock state $| 5\rangle$ well above $40\,\%$.Comment: 12 pages, 8 figure

Has the brain size decreased since the upper paleolithic period ? / La taille du cerveau a-t-elle diminué depuis le Paléolithique supérieur ? (en anglais)

Summary. — This paper shows that the process of the decrease of the size of neurocranium has occured in a world-wide range, beginning from the Upper Paleolithic Period. This process may be probably explained by an impoverishment in animal proteins, i.e. as an ecosensitive change.LA TAILLE DU CERVEAU A-TELLE DIMINUÉ DEPUIS LE PALÉOLITHIQUE SUPÉRIEUR? Résumé. — Cette publication montre que le processus de diminution de taille du neurocrâne s'est produit sur toute l'étendue du globe et a commencé au Paléolithique supérieur. On peut probablement expliquer cela par un appauvrissement dans les protéines animales, correspondant à un changement écosensitif.Wiercinski A. Has the brain size decreased since the upper paleolithic period ? / La taille du cerveau a-t-elle diminué depuis le Paléolithique supérieur ? (en anglais). In: Bulletins et Mémoires de la Société d'anthropologie de Paris, XIII° Série. Tome 6 fascicule 4, 1979. pp. 419-427