Nature Physics

Nature Physics, Published online: 24 September 2020; doi:10.1038/s41567-020-01054-6

The particle physics community refreshes the roadmap for the field in Europe, taking into account the worldwide context, in the so-called European Strategy for Particle Physics update, which happens every seven years.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-0981-y

A time–information uncertainty relation in thermodynamics has been derived, analogous to the time–energy uncertainty relation in quantum mechanics, imposing limits on the speed of energy and entropy exchange between a system and external reservoirs.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-1034-2

Ultrasound experiments reveal a multicomponent superconducting order parameter in Sr2RuO4.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-1018-2

The phrase ‘arrow of time’ refers to the asymmetry in the flow of events. A machine learning algorithm trained to infer its direction identifies entropy production as the relevant underlying physical principle in the decision-making process.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-1032-4

Ultrasound measurements show that the superconducting order parameter in strontium ruthenate must have two components.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-1020-8

An atomic spin oscillator coupled to a mechanical membrane resonator forms an effective negative-mass oscillator. Entanglement in this hybrid quantum system is created by a backaction-evading position measurement, despite the macroscopic separation.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-1035-1

Many-body localization—a phenomenon where an isolated system fails to reach thermal equilibrium—has been studied with a programmable quantum processor, which reveals the crucial role played by the initial energy on the onset of localization.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-1033-3

Ultrasound experiments show that the superconducting order parameter in strontium ruthenate must have two components.

Nature Physics, Published online: 21 September 2020; doi:10.1038/s41567-020-0991-9

The authors investigate the role of spherical confinement and curvature-induced topological defects on the crystallization of charged colloids. They conclude that crystallization in spherical confinement is due to a combination of thermodynamics and kinetic pathways.

Nature Physics, Published online: 14 September 2020; doi:10.1038/s41567-020-1002-x

Bacteria live in heterogeneous environments, so it is important to investigate their behaviour in porous media. Here the authors show that flow disorder enhances the effect of chemical gradients in micropockets in a porous medium, which then aid the transport of bacteria.

Nature Physics, Published online: 14 September 2020; doi:10.1038/s41567-020-0995-5

A new form of superradiance is predicted that ‘in contrast to the standard effect’ arises even for vanishing numbers of particles per wavelength. This finding may enable coherent emission in plasma accelerators.

Nature Physics, Published online: 14 September 2020; doi:10.1038/s41567-020-0973-y

A weak-to-strong quantum measurement transition has been observed in a single-trapped-ion system, where the ion’s internal electronic state and its vibrational motion play the roles of the measured system and the measuring pointer.

Nature Physics, Published online: 14 September 2020; doi:10.1038/s41567-020-1030-6

Transport measurements show that spontaneous symmetry breaking plays a crucial role in the correlated insulating and metallic states in twisted double bilayer graphene.

Nature Physics, Published online: 07 September 2020; doi:10.1038/s41567-020-1008-4

The radiation emission rate from gravity-related wave function collapse is calculated and the results of a dedicated experiment at the Gran Sasso laboratory are reported, ruling out the natural parameter-free version of the Diósi–Penrose model.

Nature Physics, Published online: 07 September 2020; doi:10.1038/s41567-020-1009-3

Numerical calculations that include the quantum fluctuations of protons explain the optical properties of hydrogen at high pressure.

Nature Physics, Published online: 07 September 2020; doi:10.1038/s41567-020-1016-4

Softness, a machine-learned structural quantity, has been recently identified as a parameter that characterizes glassy dynamics. Here, the authors observe devitrification in 3D soft colloidal glasses and find that softness may indicate regions predisposed to crystallization.

Nature Physics, Published online: 07 September 2020; doi:10.1038/s41567-020-1026-2

Although quantum mechanics is essential to understand microscopic systems, it has little effect on heavier objects. Experiments have now put strict constraints on theories that use gravity to explain the absence of large-scale quantum effects.

Nature Physics, Published online: 07 September 2020; doi:10.1038/s41567-020-1017-3

By incorporating a ferromagnetic layer in their superconductor–semiconductor nanowire hybrid device, Vaitiekėnas et al. show that zero-bias peaks—potential Majorana bound states—can be induced without an external magnetic field.

Nature Physics, Published online: 03 September 2020; doi:10.1038/s41567-020-01044-8

The other corona

Nature Physics, Published online: 03 September 2020; doi:10.1038/s41567-020-1022-6

Wolfgang Pauli introduced the Bohr magneton as a fundamental unit of magnetic moment during an effort to find a quantum basis for magnetism, as Davide Castelvecchi recounts.