An algorithm that shapes objects to cause them to roll down ramps following a desired path

Phys.org  August 12, 2023 The rolling paths of oloids, sphericons, polycons, platonicons and two-circle rollers are all sinusoid-like and their diversity ends there. To find out if a more general problem is solvable, an international team of researchers (South Korea, Switzerland) developed an algorithm to design such bodies (they called ‘trajectoids’) and validated these designs experimentally by three-dimensionally printing the computed shapes and tracking their rolling paths, including those that close onto themselves such that the body’s centre of mass moves intermittently uphill. According to the researchers the existence of trajectoids for most paths has unexpected implications for quantum and […]

Toward practical quantum optics: Multiphoton qubits from LNOI

Phys.org February 8, 2023 The large-photon-number quantum state is a fundamental but nonresolved request for practical quantum information applications. Researchers in China have proposed a N-photon state generation scheme that is feasible and scalable using lithium niobate on insulator circuits. The scheme was based on the integration of a common building block photon-number doubling unit (PDU) for deterministic single-photon parametric downconversion and upconversion. The PDU relies on a 107-optical-quality-factor resonator and mW-level on-chip power, which is within the current fabrication and experimental limits. N-photon state generation schemes, with cluster and Greenberger–Horne–Zeilinger state as examples, are shown for different quantum tasks… read more. […]

Quantum technology reaches unprecedented control over captured light

Phys.org  September 27, 2022 An international team of researchers (Sweden, Japan) has developed a technique to overcome to noise and interference in quantum systems. Their technique could create any of the previously demonstrated states and the cubic phase state. They used a sequence of interleaved selective number-dependent arbitrary phase (SNAP) gates and displacements. The state preparation was optimized in two steps – first they used a gradient-descent algorithm to optimize the parameters of the SNAP and displacement gates; then optimized the envelope of the pulses implementing the SNAP gates. The results showed that this way of creating highly nonclassical states […]

Tailored single photons: Optical control of photons as the key to new technologies

Nanowerk April 6, 2022 Several different approaches to realize solid-state quantum emitters with high performance have been pursued and different concepts for energy tuning have been established. However, the properties of the emitted photons are always defined by the individual quantum emitter and can therefore not be controlled with full flexibility. An international team of researchers (Germany, USA – University of Arizona) has developed an all-optical nonlinear method to tailor and control the single photon emission. They demonstrated a laser-controlled down-conversion process from an excited state of a semiconductor quantum three-level system. Based on this concept, they realized energy tuning […]

Looking at optical Fano resonances under a new light

Phys.org  March 19, 2021 Fano resonances are conventionally understood as sharp spectral features that can be excited only by plane waves with specific frequencies and incident angles. Researchers at the City University of New York proved that they can be tailored to resonate only when excited by a frequency, polarization, and wavefront of choice. This generalization reveals that Fano systems are characterized by eigenwaves that scatter to their time-reversed image upon reflection. They showed that the selected wavefront is locally retroreflected everywhere across the device. These results show that conventional Fano resonances are a subset of a broader dichroic phenomenon […]

Tiny device enables new record in super-fast quantum light detection

EurekAlert  November 9, 2020 An international team of researchers (UK, France) has made a new miniaturized device by interfacing CMOS-compatible silicon and germanium-on-silicon nanophotonics with silicon-germanium integrated amplification electronics. The detector has a 3 dB bandwidth of 1.7 GHz, is shot noise limited to 9 GHz and has a miniaturized required footprint of 0.84 mm2. The detector can measure the continuous spectrum of squeezing from 100 MHz to 9 GHz of a broadband squeezed light source pumped with a continuous-wave laser. The research provides fast, multipurpose, homodyne detectors for continuous-variable quantum optics, and opens the way to full-stack integration of photonic quantum devices…read more. TECHNICAL ARTICLE

A new path for electron optics in solid-state systems

Science Daily  July 14, 2020 Electron optics has been demonstrated mainly in one-dimensional devices, for example in nanotubes. Researchers in Switzerland have shown that the band inversion and hybridization present in two coupled semiconductor layers, consisting of InAs and GaSb system provide a novel transport mechanism that guarantees non-vanishing interference even when all angles of incidence occur. Through a combination of transport measurements and theoretical modelling, they found that their devices operate as a Fabry-Pérot interferometer in which electrons and holes form hybrid states. As the mechanism requires only band inversion and hybridization, the research opens engineering electron-optical phenomena in […]

Quantum researchers able to split one photon into three

Phys.org  February 27, 2020 By splitting one “pump photon” into two daughter photons, SPDC has had a crucial role in fundamental tests of quantum theory as well as many applications in quantum information processing. An international team of researchers (Canada, Spain, Sweden) used a flux-pumped, superconducting parametric resonator to split one microwave photon into three daughter photons. The triplet source is bright, producing a propagating photon flux comparable to ordinary two-photon SPDC. They clearly saw strong three-photon correlations in the output photons, even in the absence of normal two-photon correlations. The symmetry properties of these correlations allowed them to “fingerprint” […]