Themed collection Nanoscale quantum technologies

Qing Dai, Chao-Yang Lu and Zhipei Sun introduce the Nanoscale themed collection on Nanoscale quantum technologies.

Silicon photonics is rapidly evolving as an advanced chip framework for implementing quantum technologies.

Cavity optomechanics investigates the interaction between electromagnetic waves and mechanical motion enhanced by the resonant cavity. In cavity-less exciton optomechanics, the resonant cavity is replaced by excitonic resonance.

SPDC in a metasurface with the signal and idler photons emitted in opposite directions.

A terahertz multi-optical mode cavity optomechanical device is designed using a topological superlattice and Ω_m=ω_j-ω_j-1≠ω_j+1-ω_j. Scattering photons could doubly resonate with cavity modes at an anti-Stokes (Stokes) frequency and pump frequency.

Non-integrated correlative light-electron microscopy with nitrogen vacancy sensing on transmission electron microscopy finder grids for the study of paramagnetic Prussian blue analogue nanoparticles.

Novel, vertically oriented self-assembly of core/shell CdSe/CdZnS colloidal quantum wells stacked in film via the control of hydrophilicity/lipophilicity is shown for optical gain media, allowing amplified spontaneous emission and random lasing.

Magnetic ordering of 2D auxetic magnets is more stable than that of non-auxetic ones under mono-axial strain.

We determine the spin transfer torque due to TI bulk states, showing that it has a distinguishable signature and can be sizeable in real samples.

By obtaining the real magnetic anisotropy energy (MAE) under different strains, when 1.5% < ε < 1.8%, due to spontaneous valley polarization, intrinsic out-of-plane (OOP) magnetic anisotropy, and a chiral edge state, the VQAHE can reliably appear between two HVM states.

Quantum plasmonics enhance photoluminescence in two-dimensional heterostructures.

In this study, we demonstrate uniform Ge hut wire arrays on a flattened surface by multi-layer growth of strained Ge(Si) layers separated with Si spacer layers on top of site-controlled GeSi hut wires.

By performing ultrafast nonlinear spectroscopy, we assess the optical coherence of MoSe₂ monolayers grown by molecular beam epitaxy.

The nanopost single-photon source exhibits surprisingly high collection efficiency, despite its geometrical simplicity, due to beneficial scattering into radiation modes.

With pulse sequences of structured light, we achieve robust ultrafast high-fidelity C-PHASE gates in non-independent atomic qubits. The optimal protocols form lattices in parameter space rotated by an angle that depends on the proximity of the qubits.

A practical construction method for on-chip surface-emitting light sources on silicon-based integrated photonic devices, demonstrated with a SiN photonic crystal cavity on CdSe/ZnS quantum dots.

The nodal loop phase transition to Weyl fermion in twisted-brick-MoTe is realized via spin–orbit interactions. Strain effects can tune the topological strength strikingly; hence, a strain-tuned partly-ideal Weyl semimetal phase in MoTe was observed.

We report an insulator-to-metal phase transition in a few-layer MoSe₂ field-effect transistor. The conductivity (shown in figure) becomes metallic at a critical carrier density of 1.2 x 10¹² cm^-2 and is analyzed using percolation theory.

The control of the ferroelectric domains in this valley valve allows generating and tuning topological excitations, thus providing a promissing platform to print circuits displaying a ballistic behavior.

Single photon purity of an individual quantum dot is severely compromised by biexciton emission. Giant shell quantum dots are allowing for biexciton spectral separation with a long-pass filter improving single photon purity at room temperature.

Perovskites quantum dots coupled to Mie resonators display an 18-fold luminescence enhancement. Spatially- and time-resolved measurements, coupled to numerical simulations, confirm increased absorption, Purcell factor and extraction efficiency.

The authors present the dependence of the timing jitter of superconducting nanowire single-photon detectors on the multi-layer sample design and slew rate.

A multicolor AC-driven light-emitting device by integrating a WSe₂ monolayer and AlGaInP–GaInP multiple quantum well (MQW) structures.

We investigate repeatable and reliable tuning of single organic molecule fluorescence by applying strain via a piezoelectric substrate.

We investigate the key photophysical properties of NIR quantum emitters from point defects in AlGaN films both theoretically and experimentally.

Valley polarization is a new resource for optoelectronics and information technologies. This article demonstrates the critical role of indirect transitions in protecting valley polarization in few-layer WS₂ and WSe₂.

With recent advances in GaN LED technology, we explore a new class of compact, stand-alone transition metal dichalcogenide electroluminescence devices.

A schematic diagram of the proposed design scheme for highly-efficient radiative thermal rectifiers based on thermally-induced near-field gap variations.

We maped in real space the propagative exciton–plasmon polaritons in WSe₂/Au heterostructures. These polaritons are formed due to the strong coupling between excitons in WSe₂ and surface plasmon polaritons on Au.

Tuning the charge transport properties of two-dimensional transition metal dichalcogenides (TMDs) is pivotal to their future device integration in post-silicon technologies.

Spin defects in hexagonal boron nitride are coupled to microring cavity resonator.

Single charge control of localized excitons has been demonstrated in heterostructures with ferroelectric thin films and two-dimensional transition metal dichalcogenides, which are confirmed with magneto-photoluminescence spectroscopy.

Machine learning is used to improve in situ electron beam lithography capabilities. Specially trained algorithms increase the sensitivity by more than a factor of 10 in the deterministic processing of high-performance quantum light sources.