Causal viewpoint and ensemble interpretation: from physics to the social sciences.

In this article, we assert that, for the construction of quantum physics-analogous (as opposed to quantum math-analogous) probabilistic models of the social (e.g. economics-financial) reality, the use of the notion of causality and the idea of an ensemble of similarly prepared systems in a socially analogous manner could be essential. We give plausibility arguments in favour of this assertion by considering two social situations describable in terms of discrete-time stochastic (i.e. Markov) processes. The first one is an arbitrary economics/financial context expressed as a temporal sequence of actualized social states (e.g. decisions, choices, preferences, etc.). The other one is more specific, involving a generic supply chain context. This article is part of the theme issue 'Thermodynamics 2.0: Bridging the natural and social sciences (Part 1)'.

Investigation of the Leggett-Garg inequality for precessing nuclear spins.

We report experimental implementation of a protocol for testing the Leggett-Garg inequality (LGI) for nuclear spins precessing in an external magnetic field. The implementation involves certain controlled operations, performed in parallel on pairs of spin-1/2 nuclei (target and probe) from molecules of a nuclear magnetic resonance ensemble, which enable evaluation of temporal correlations from an LG string. Our experiment demonstrates violation of the LGI for time intervals between successive measurements, over which the effects of relaxation on the quantum state of target spin are negligible. Further, it is observed that the temporal correlations decay, and the same target spin appears to display macrorealistic behavior consistent with LGI.

Superpositions of chiral states in the presence of electric dipole, magnetic dipole, and electric quadrupole interactions.

This paper is a straightforward generalization of Maierle-Harris proposal regarding parity implications on the superpositions of chiral states of a molecule. It is shown that the inclusion of electric quadrupole and magnetic dipole interactions removes several of restrictions on the preparation of superpositions of mid R:L and mid R:R states of a chiral molecule. It is also found that the dephasing of mid R:L and mid R:R superpositions, due to the spontaneous emission from the chiral molecule, has opposing contributions from electric quadrupole-magnetic dipole and electric dipole interactions.