Volume 16 Issue 8, August 2020

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.

Error-corrected quantum gates that can tolerate dominant errors during the execution of quantum operations have been demonstrated. Substantial improvement of the gate fidelity sheds light on fault-tolerant universal quantum computation.

Error-transparent quantum gates that can tolerate certain error during the execution of quantum operations have been demonstrated. Substantial improvement of the gate fidelity sheds lights on large-scale universal quantum computation.

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.

α-RuCl₃ is a promising candidate for realizing the Kitaev quantum spin liquid, but the physics governing its magnetic behaviour remain elusive. Resonant elastic X-ray scattering data now set unambiguous constraints on the leading terms in the Hamiltonian.

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.

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.

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.

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.

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.

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.

In a surface code consisting of four data and three ancilla qubits, repeated error detection is demonstrated. The lifetime and coherence time of the logical qubit are enhanced over those of any of the constituent qubits when no errors are detected.

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.

Giacomo Prando summarizes the troubled history of the radian, a unit with the odd property of appearing and disappearing seemingly at will in dimensional formulas.