2 results
Carrier transport, recombination, ion migration and phase segregation govern optoelectronic devices across nanometre-to-micrometre distances and picosecond-to-hour timescales. Conventional measurements obscure this heterogeneity. Sudipta Seth presents optical microscopy and spectroscopy that convert local material function into spatially and temporally resolved contrast under working conditions. Applied to halide perovskites, these methods expose local fields, transport bottlenecks and defect chemistry affecting solar-cell performance. The resulting mechanisms guide improved probes, interfaces and devices. The webinar is intended for materials researchers, microscopists and spectroscopists and includes questions.
Tue, Nov 3 · 16:00 UTC · Online
Intermediate-band solar cells seek to absorb photons below the host band gap and increase current without sacrificing voltage. This talk examines submonolayer CdTe quantum dots embedded in ZnCdSe matched to InP, avoiding a harmful wetting layer and permitting hundreds of absorbing layers. Recent growth results show deeper photoluminescence associated with larger dots and improved intermediate-band placement. A complementary inverse-design study optimizes ZnCdSe/ZnCdMgSe distributed Bragg reflectors to recycle photons over 1–1.8 micrometres and incidence angles of 0–70 degrees. Total absorption guides optimization, with designs showing broad reflectivity and tolerance to fabrication errors.
Mon, Nov 9 · 17:15 UTC · Online
Tracy Northup explains how interactions between trapped atomic ions and single photons transfer quantum information between matter and light. Atom–photon entanglement can connect distant ions, as demonstrated by a prototype linking calcium ions across 230 metres. The seminar considers how larger networks could support secure communications, distributed computation and connected quantum sensors.
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Quantum networks require links between stored qubits and information carried by travelling waves. This lecture compares interfaces coupling atoms, spins and superconducting circuits to optical or acoustic signals. It also introduces quantum memories, the measurements used to assess their performance, recent experimental results and applications that combine communication with quantum processing.
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Gerhard Rempe explores how to create useful entanglement across many qubits. Individual atoms in an optical cavity generate photons with controllable graph-shaped entanglement patterns. The seminar examines the experimental challenge of producing these states on demand and their potential for photonic error correction, quantum computation and communication that tolerates photon loss.
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Photonic quantum processors use interference between indistinguishable photons to manipulate information. This lecture reviews proposed architectures and experiments involving several dozen photons. It then examines measurement-based computation as a route toward larger systems, including highly entangled light, error correction, distributed processing and possible integration with spin qubits.
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Reliable photon sources are essential for optical quantum communication and computation. This lecture compares single-photon generation through nonlinear optical processes with controlled emission from individual atoms. It discusses performance, limitations and integration, then extends the comparison to sources of entangled photons and more elaborate quantum states of light.
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Mete Atatüre examines semiconductor quantum dots as interfaces between photons, electron spins and ensembles of nuclear spins. Optical control can turn the nuclear environment from a source of noise into a useful quantum system. The seminar follows this progression through collective nuclear states toward a register capable of storing quantum information.
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