Nature Physics

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0914-9

The cores of neutron stars could be made of hadronic matter or quark matter. By combining first-principles calculations with observational data, evidence for the presence of quark matter in neutron star cores is found.

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0917-6

Repulsive photons in a quantum nonlinear medium

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0922-9

Boundary-localized bulk eigenstates given by the non-Hermitian skin effect are observed in a non-reciprocal topological circuit. A fundamental revision of the bulk–boundary correspondence in an open system is required to understand the underlying physics.

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0918-5

The Rydberg-atom superhet, based on microwave-dressed Rydberg atoms and a tailored electromagnetically induced transparency spectrum, allows SI-traceable measurements of microwave electric fields with unprecedented sensitivity.

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0909-6

Braneworld cosmologies describe our universe as a four-dimensional membrane embedded in a bulk five-dimensional anti-de Sitter spacetime. In a possible holographic realization, observers on the brane experience cosmology, and gravity is localized.

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0928-3

Here, it is shown that superconductivity can exist without correlated insulating states in twisted bilayer graphene devices a little away from the magic angle. This indicates the two phases compete with each other, in contrast to previous claims.

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0913-x

In the interaction of ultraintense, short laser pulses with solid targets, the collisionless Weibel instability is observed. For a sufficiently high resistivity of the target, an additional resistive instability appears.

Nature Physics, Published online: 01 June 2020; doi:10.1038/s41567-020-0908-7

The localization properties of waves in the quasiperiodic chains described by the Aubry–André model and Fibonacci model are investigated. Passing from one model to the other, the system develops a cascade of delocalization transitions.

Nature Physics, Published online: 26 May 2020; doi:10.1038/s41567-020-0929-2

Automated learning from data by means of deep neural networks is finding use in an ever-increasing number of applications, yet key theoretical questions about how it works remain unanswered. A physics-based approach may help to bridge this gap.

Nature Physics, Published online: 25 May 2020; doi:10.1038/s41567-020-0921-x

This Perspective argues that an approach called extreme value theory is appropriate for understanding the so-called tail risk of epidemic outbreaks, in particular by demonstrating that the distribution of fatalities due to epidemic outbreaks over the past 2500 years is fat-tailed and dominated by extreme events.

Nature Physics, Published online: 25 May 2020; doi:10.1038/s41567-020-0890-0

When interfacing a graphene layer with a thin solid emitter, the quantum plasmonic vacuum allows each solid electron to access all unoccupied valence states through the nonlocality of their light-matter interaction, creating ultra-strong coupling alongside mass and bandgap renormalization.

Nature Physics, Published online: 25 May 2020; doi:10.1038/s41567-020-0910-0

A careful study of quantum oscillations of single crystals of the cuprate superconductor YBCO placed under a magnetic field reveals a sawtooth behaviour that is reminiscent of two-dimensional electronic systems—in turn suggesting the existence of a so-called ‘hard antinodal gap’ in this system.

Nature Physics, Published online: 25 May 2020; doi:10.1038/s41567-020-0903-z

High entanglement fidelity between neutral atoms is achieved using highly excited Rydberg states. The unique electron structure provided by alkaline-earth atoms makes it a promising platform for various quantum-technology-based applications.

Nature Physics, Published online: 25 May 2020; doi:10.1038/s41567-020-0907-8

Systems of neutral atoms are gradually gaining currency as a promising candidate for realizing large-scale quantum computing. The achievement of a record-high fidelity in quantum operation with alkaline-earth Rydberg atoms is a case in point.

Nature Physics, Published online: 19 May 2020; doi:10.1038/s41567-020-0906-9

The identification of superconductivity and strong interactions in twisted bilayer 2D materials prompted many questions about the interplay of these phenomena. This Perspective presents the status of the field and the urgent issues for future study.

Nature Physics, Published online: 18 May 2020; doi:10.1038/s41567-020-0898-5

The interface between a quantum Hall state and a superconductor hosts topological modes. Here, interference between two such modes turns an electron into either a hole or an electron depending on the phase difference along the interference path.

Nature Physics, Published online: 18 May 2020; doi:10.1038/s41567-020-0899-4

The intrinsic dipole moment of 228Th is reported, from which the degree of the nucleus’s octupole deformation is estimated, suggesting that 229Th and 229Pa may be suitable candidates for the search for a permanent atomic electric dipole moment.

Nature Physics, Published online: 18 May 2020; doi:10.1038/s41567-020-0891-z

By exploiting the long-lived phonon modes in nanoscale mechanical resonators, a quantum memory that operates around the standard telecom wavelength of 1,550 nm is realized on a silicon platform.

Nature Physics, Published online: 11 May 2020; doi:10.1038/s41567-020-0886-9

An exotic s + is multiband superconducting state manifests in a doped pnictide superconductor when a second band moves below the Fermi surface. This creates an internal magnetic field, breaking time-reversal symmetry.

Nature Physics, Published online: 11 May 2020; doi:10.1038/s41567-020-0892-y

Transmitting the time signal and generating the secure key with the same carrier photon improves the security of a satellite-based quantum-secure time transfer protocol, which uses two-way quantum key distribution.