Did you know that you can find CQT on YouTube? Visit our channel for videos of scientific colloquiua given at the Centre and other short films about quantum physics. Newest in our archive is a talk by Robert Taylor of the University of Oxford on "Photonic Crystals and Photonic Molecules at Telcom Wavelengths".
Transition probabilities in Barium found to within 1%, paving way to search for physics beyond the Standard Model
Some 300 scientists attended QCMC 2016, including special sessions on loophole-free Bell tests and industrial efforts
Thirteen students with the Centre have been awarded PhD degrees in 2016
- Quantum Thermodynamic Series: Talk by Konstantin Dorfman, University of California — 29 Aug, 12:30 PM
- CQT Talk by Michael Block, University of Mainz — 09 Sep, 10:30 AM
Quantum Thermodynamic Series: Talk by Konstantin Dorfman, University of California
Title: Quantum Heat Engine Enhanced by Coherence: Is it possible to go beyond Chambadal-Novikov-Curzon-Ahlborn Limit?
Date/Time: 29 Aug, 12:30 PM
Venue: CQT Level 3 Seminar Room, S15-03-15
Various quantum effects have been observed in the thermodynamic of small systems. For instance understanding the microscopic origin of the quantum coherence and its role in the energy and charge transfer processes along with thermodynamics characteristics of the small systems is a key problem in both thermodynamics and quantum mechanics.
We had investigated the possible role of quantum coherence and interference on steady state and transient behavior of the quantum heat engines (QHE), e.g lasers, photovoltaic cells, photosynthetic reaction centers, and nanoplasmonic devices. We showed that the maximum power of a QHE that converts incoherent thermal energy into coherent cavity photons could be enhanced by manipulating quantum coherences. We demonstrated that in both artificial (solar cells) and natural (photosynthesis) light harvesting coherence affects the same population–coherence coupling term which is induced by bath (e.g. phonons), does not require coherent light, and will therefore work for incoherent excitation under natural conditions of solar excitation.
We further investigate a novel model of the three-level laser QHE where lasing occurs between two closely spaced metastable states and the ground stated. Engine operates by transferring energy from hot bath to cold bath via nonequilibrium coherence assisted process. Coherence has two sources: first is due to quantum interference generated via hot bath and second is due to the lasing field coupled to both metastable states. The resulting efficiency at maximum power can be significantly improved due to interplay between these two coherence contributions.
CQT Talk by Michael Block, University of Mainz
Title: Investigating Atomic and Nuclear Properties of the Heaviest Elements at GSI
Date/Time: 09 Sep, 10:30 AM
Venue: CQT Level 3 Seminar Room, S15-03-15
The heaviest elements with Z > 100 attract interest from nuclear and atomic phys ics due to their distinct properties. Nuclear shell effects are responsible for their very existence stabilizing them against immediate dis integration by spontaneous f ission. Strong relativistic effects influence their electronic structure and chemical behavior as certain orbita ls are stabilized while others become less bound. Precision measurements of different atomic and nuclear properties improve our understanding of these exotic objects and probe the nature of the underlying forces. Accurate experimental data also challenge theoretical predictions and contribute to their impr ovement. Numerous precision measurements of ground state properties of radionuclides across the nuclear chart have been obtained in recent years utilizing ion trap and laser spectroscopy-based techniques. New methods for slow ing down high-energy beams in buffer gas cells have opened the door to extend such experiments to the heaviest nuclides. I will discuss recent developments for high-precis ion mass measurements with the Penning trap system SHIPTRAP at GSI Darmstadt. In addition, I w ill present the latest results of pioneering resonance ionization laser spectroscopy experiments on nobelium (Z=102).
- Multi-photon absorption in optical gratings for matter waves
- Characterization of very narrow spectral lines with temporal intensity interferometry
- Topological pumping of photons in nonlinear resonator arrays
- Driven open quantum systems and Floquet stroboscopic dynamics
- Scalable architecture for Atomtronics flux qubits