Free motion of a quantum particle with the wave function entirely comprised plane waves non-negative momenta may be accompanied by negative probability current, an effect called backflow. The is weak and fragile has not yet been observed experimentally. Here we show that backflow becomes significantly more pronounced amenable to experimental observation if, instead letting move along straight l...

Several difurylperfluorocyclobutenes showing reversible photochromism were synthesized. In comparison to their cyclopentene homologues they show enhanced quantum yields for ring opening but reduced quantum yields for ring closure. X-ray structure analysis and quantum chemical calculations provide a conclusive explanation for such a behaviour.

We compare the Chen-Ruan cohomology ring of the weighted projective spaces P(1, 3, 4, 4) and P(1, ..., 1, n) with the cohomology ring of their crepant resolutions. In both cases, we prove that the Chen-Ruan cohomology ring is isomorphic to the quantum corrected cohomology ring of the crepant resolution after suitable evaluation of the quantum parameters. For this, we prove a formula for the Gro...

We study the effect of tunneling on the electronic structure of two vertically coupled quantum rings within the spin density functional theory. The ground state configurations of the coupled rings are obtained for a system with 10 electrons as a function of the ring radius and the inter-ring distance. For small ring radius, our results recover those of coupled quantum dots. For large ring radiu...

The universal enveloping algebra U (G) of a Lie algebra G acts on its representation ring R through D(R), the ring of differential operators on R. A quantised universal enveloping algebra (or quantum group) is a deformation of a universal enveloping algebra and acts not through the differential operators of its representation ring but through the quantised differential operators of its represen...

The universal enveloping algebra U (G) of a Lie algebra G acts on its representation ring R through D(R), the ring of differential operators on R. A quantised universal enveloping algebra (or quantum group) is a deformation of a universal enveloping algebra and acts not through the differential operators of its representation ring but through the quantised differential operators of its represen...

We present two models of coherent quantum switches constructed from a single-electron quantum ring and a double quantum dot, respectively. The systems are driven by picosecond laser pulses obtained using quantum optimal control theory. The optimized pulses generate electron-current flips in the ring (magnetic switch) and electron transport in the double dot (charge switch) in significantly shor...

Let V be a symplectic vector space and LG be the Lagrangian Grassmannian which parametrizes maximal isotropic subspaces in V . We give a presentation for the (small) quantum cohomology ring QH∗(LG) and show that its multiplicative structure is determined by the ring of Q̃-polynomials. We formulate a ‘quantum Schubert calculus’ which includes quantum Pieri and Giambelli formulas, as well as algor...

A quantum circuit rule for combining quantum interference effects in the conductive properties of oligo(phenyleneethynylene) (OPE)-type molecules possessing three aromatic rings was investigated both experimentally and theoretically. Molecules were of the type X-Y-X, where X represents pyridyl anchors with para (p), meta (m) or ortho (o) connectivities and Y represents a phenyl ring with p and ...