Researchers create antenna for nanoscale light sources using unusual placement of semiconductor material

Phys.org  July 3, 2023 Two-dimensional van der Waals materials are an excellent platform for the study of materials with well-defined interfaces. Signatures of acoustic phonons and defect states have been observed in current-to-voltage measurements. These features can be explained by direct electron–phonon or electron–defect interactions. An international team of researchers (Switzerland, Spain, Japan) used a tunnelling process that involved excitons in transition metal dichalcogenides (TMDs). They studied the tunnel junctions consisting of graphene and gold electrodes separated by hexagonal boron nitride with an adjacent TMD monolayer and observed prominent resonant features in current-to-voltage measurements appearing at bias voltages that corresponded […]

Researchers develop a light source that produces two entangled light beams

Phys.org  January 3, 2023 In quantum entanglement when the systems interact with their surroundings, they almost immediately become disentangled. An international team of researchers (Brazil, USA – University of Oklahoma) produced a light source that produced two entangled light beams. The twin beams generated with a doubly resonant optical parameter oscillator (OPO) based on four-wave mixing in hot 85Rb vapor above threshold. They reconstructed the covariance matrix for several configurations and based on a full picture of the four-side band mode state, they studied entanglement between all possible bipartitions. They showed a robust generation of entanglement with stronger generation for […]