Complementary weak-value amplification with concatenated postselections

We measure a transverse momentum kick in a Sagnac interferometer using weak-value amplification with two postselections. The first postselection is controlled by a polarization dependent phase mismatch between both paths of a Sagnac interferometer and the second postselection is controlled by a polarizer at the exit port. By monitoring the darkport of the interferometer, we study the complementary amplification of the concatenated postselections, where the polarization extinction ratio is greater than the contrast of the spatial interference. In this case, we find an improvement in the amplification of the signal of interest by introducing a second postselection to the system

Optical Absorptivity versus Molecular Composition of Model Organic Aerosol Matter

Aerosol particles affect the Earth’s energy balance by absorbing and scattering radiation according to their chemical composition, size, and shape. It is generally believed that their optical properties could be deduced from the molecular composition of the complex organic matter contained in these particles, a goal pursued by many groups via high-resolution mass spectrometry, although: (1) absorptivity is associated with structural chromophores rather than with molecular formulas, (2) compositional space is a small projection of structural space, and (3) mixtures of polar polyfunctional species usually exhibit supramolecular interactions. Here we report a suite of experiments showing that the photolysis of aqueous pyruvic acid (a proxy for aerosol α-dicarbonyls absorbing at λ > 300 nm) generates mixtures of identifiable aliphatic polyfunctional oligomers that develop absorptions in the visible upon standing in the dark. These absorptions and their induced fluorescence emissions can be repeatedly bleached and retrieved without carbon loss or ostensible changes in the electrospray mass spectra of the corresponding mixtures and display unambiguous signatures of supramolecular effects. The nonlinear additivity of the properties of the components of these mixtures supports the notion that full structural speciation is insufficient and possibly unnecessary for understanding the optical properties of aerosol particles and their responses to changing ambient conditions

Can Anomalous Amplification be Attained Without Postselection?

We present a parameter estimation technique based on performing joint measurements of a weak interaction away from the weak-value-amplification approximation. Two detectors are used to collect full statistics of the correlations between two weakly entangled degrees of freedom. Without the need of postselection, the protocol resembles the anomalous amplification of an imaginary-weak-value-like response. The amplification is induced in the difference signal of both detectors allowing robustness to different sources of technical noise, and offering in addition the advantages of balanced signals for precision metrology. All of the Fisher information about the parameter of interest is collected, and a phase controls the amplification response. We experimentally demonstrate the proposed technique by measuring polarization rotations in a linearly polarized laser pulse. The effective sensitivity and precision of a split detector is increased when compared to a conventional continuous-wave balanced detection technique

Thermochromism of Model Organic Aerosol Matter

Laboratory experiments show that the optical absorptivity of model organic matter is not an intrinsic property, but a strong function of relative humidity, temperature, and insolation. Suites of representative polyfunctional C_(x)H_(y)O_(z) oligomers in water develop intense visible absorptions upon addition of inert electrolytes. The resulting mixtures reach mass absorption cross sections σ(532 nm) ~ 0.1 m^(2)/gC in a few hours, absorb up to 9 times more solar radiation than the starting material, can be half-bleached by noon sunlight in ~ 1 h, and can be repeatedly recycled without carbon loss. Visible absorptions red-shift and evolve increasingly faster in subsequent thermal aging cycles. Thermochromism and its strong direct dependences on ionic strength and temperature are ascribed to the dehydration of >CH−C(OH)C═C< unsaturations by a polar E1 mechanism, and bleaching to photoinduced retrohydration. These transformations are deemed to underlie the daily cycles of aerosol absorption observed in the field, and may introduce a key feedback in the earth’s radiative balance

José Luís López-Aranguren: l'eticitat de l'Estat com a fonament de l'educació per a la participació ciutadana = José Luís López-Aranguren: The ethics of the State like foundation of the education for the civil participation

L'educació cívica per a la formació política d'una ciutadania participativa en els afers que són de tots és una tasca fonamental que ha de dur-se a terme des d'un Estat fort, èticament moral: un Estat que no caigui en els errors de l'adoctrinament, però que tampoc deixi la dita formació a les mans del poder establit perquè la utilitzi com un instrument al servei de la ideologia dominant de torn. Es tracta d'una educació que ajudi a la societat civil en la tasca de la democratització real i moral de la societat i les seves institucions. En aquest article presento una aproximació a la proposta d'Estat de justícia social del professor José Luis López-Aranguren consistent en la construcció d'un Estat ètic, on la moral estigui inscrita en les seves pròpies estructures jurídiques i administratives. Es tracta d'un Estat ètic que, no obstant això, no desatén el necessari paper que la ciutadania, individualment o col·lectivament considerada, ha d'exercir en la construcció d'una societat més justa, la qual cosa demanda una adequada educación moral, cívica, política i social.The civic education for the political formation of a participating citizenship in the matters that concern all of us is a fundamental task that must be carried out by a strong state, ethically moral: a state that does not fall into the errors of indoctrination, but neither does it leave this formation in the hands of the established power for it to be used as an instrument in the service of the dominant ideology of the moment. I am considering an education that would help the civilian society in the task of the real and moral democratization of society and its institutions. In this article I am developing an approach to Professor Jose Luis Lopez-Aranguren’s proposal for a state of social justice, consisting in the construction of an ethical state, where moral matters are embedded in its own legal and administrative structures. I am talking about an ethical state that, nevertheless, does not neglect the necessary role that the citizenry, individual or collectively considered, have to carry out in the construction of a more just society.La educación cívica para la formación política de una ciudadanía participativa en los asuntos que son de todos es una tarea fundamental que debe llevarse a cabo desde un estado fuerte, éticamente moral: un estado que no caiga en los errores del adoctrinamiento, pero que tampoco deje dicha formación en manos del poder establecido para que la utilice como un instrumento al servicio de la ideología dominante de turno. Se trata de una educación que ayude a la sociedad civil en la tarea de la democratización real y moral de la sociedad y sus instituciones. En este artículo presento una aproximación a la propuesta de estado de justicia social del profesor José Luis López-Aranguren, consistente en la construcción de un estado ético, donde lo moral esté inscrito en sus propias estructuras jurídicas y administrativas. Se trata de un estado ético que, sin embargo, no desatiende el necesario papel que la ciudadanía, individual o colectivamente considerada, ha de desempeñar en la construcción de una sociedad más justa, lo cual demanda una adecuada educación moral, cívica, política y social