We study the synchronization behaviors of two indirectly coupled mechanical oscillators of different frequencies in a doublecavity optomechanical system. It is found that quantum synchronization is roughly vanishing though classical synchronization seems rather good when each cavity mode is driven by an external field in the absence of temporal modulations. By periodically modulating cavity detunings or driving amplitudes, however, it is possible to observe greatly enhanced quantum synchronization accompanied with nearly perfect classical synchronization. The level of quantum synchronization observed here is, in particular, much higher than that for two directly coupled mechanical oscillators. Note also that the modulation on cavity detunings is more appealing than that on driving amplitudes when the robustness of quantum synchronization is examined against the bath’s mean temperature or the oscillators’ frequency difference.

We study the collective dynamics of a clean Floquet system of cold atoms, numerically simulating two realistic setups based on a regular chain of interacting Rydberg atoms driven by laser fields. In both cases, the population evolution and its Fourier spectrum display clear signatures of a discrete time crystal (DTC), exhibiting the appearance of a robust subharmonic oscillation which persists on a timescale increasing with the chain size, within a certain range of control parameters. We also characterize how the DTC stability is affected by dissipative processes, typically present in this atomic system even though the Rydberg state is very long lived.

We explore folk theories of sound judgment across two cultures, with a particular focus on the distinction between rationality and reasonableness and how people apply these concepts in a range of social and non-social contexts. Four studies using English-speaking samples in North America (Studies 1-3; N=1,826) and a Mandarin-speaking sample in China (Study 4; N=659) examine spontaneous descriptions of characteristics of sound judgment, preferences for and perception of agents in different social contexts (varying in demands for rule-based vs. holistic approaches to decision-making), and categorization of non-social objects. People spontaneously considered both rationality and reasonableness as central features of sound judgment and yet assigned unique attributes to these standards when mapping concept networks. In experiments, people favored rational agents for contexts demanding analytic reasoning and reasonable agents for contexts demanding interpretive/holistic reasoning. Moreover, across cultures, people used rule-based categorization for rational judgment and overall-similarity categorization for reasonable judgment of non-social objects.

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