Diagonal Slice Four-Wave Mixing: Natural Separation of Coherent Broadening Mechanisms

We present an ultrafast coherent spectroscopy data acquisition scheme that samples slices of the time domain used in multidimensional coherent spectroscopy to achieve faster data collection than full spectra. We derive analytical expressions for resonance lineshapes using this technique that completely separate homogeneous and inhomogeneous broadening contributions into separate projected lineshapes for arbitrary inhomogeneous broadening. These lineshape expressions are also valid for slices taken from full multidimensional spectra and allow direct measurement of the parameters contributing to the lineshapes in those spectra as well as our own

Hidden Silicon-Vacancy Centers in Diamond

We characterize a high-density sample of negatively charged silicon-vacancy (SiV$^-$) centers in diamond using collinear optical multidimensional coherent spectroscopy. By comparing the results of complementary signal detection schemes, we identify a hidden population of \ce{SiV^-} centers that is not typically observed in photoluminescence, and which exhibits significant spectral inhomogeneity and extended electronic $T_2$ times. The phenomenon is likely caused by strain, indicating a potential mechanism for controlling electric coherence in color-center-based quantum devices

Absolute Phase Calibration in Phase-modulated Multidimensional Coherent Spectroscopy

Establishing the correct phase in multidimensional coherent spectroscopy (MDCS) experiments is critical because the interpretation of quantum pathways is based on the phase of their associated spectral features but is not trivial because the phase introduced by experimental conditions can contaminate the signal. Most phase-modulated MDCS (PM-MDCS) experiments study molecular systems for which the spectra can be phased to produce absorptive lineshapes, but this assumption of absorptive lineshapes can break down in more complicated systems. We present a robust technique for correcting the phase in PM-MDCS experiments and demonstrate accurate spectrum phasing for an anharmonic system

Diagonal Slice Four-wave Mixing: Natural Separation of Coherent Broadening Mechanisms

We present an ultrafast coherent spectroscopy data acquisition scheme that samples slices of the time domain used in multidimensional coherent spectroscopy to achieve faster data collection than full spectra. We derive analytical expressions for resonance lineshapes using this technique that completely separate homogeneous and inhomogeneous broadening contributions into separate projected lineshapes for arbitrary inhomogeneous broadening. These lineshape expressions are also valid for slices taken from full multidimensional spectra and allow direct measurement of the parameters contributing to the lineshapes in those spectra as well as our own

Exciton-Coupled Coherent Magnons in a 2D Semiconductor

Two-dimensional (2D) magnetic semiconductors feature both tightly-bound excitons with large oscillator strength and potentially long-lived coherent magnons due to the presence of bandgap and spatial confinement. While magnons and excitons are energetically mismatched by orders of magnitude, their coupling can lead to efficient optical access to spin information. Here we report strong magnon-exciton coupling in the 2D van der Waals (vdW) antiferromagnetic (AFM) semiconductor CrSBr. Coherent magnons launched by above-gap excitation modulate the interlayer hybridization, which leads to dynamic modulation of excitonic energies. Time-resolved exciton sensing reveals magnons that can coherently travel beyond 7 micrometer, with coherence time above 5 ns. We observe this exciton-coupled coherent magnons in both even and odd number of layers, with and without compensated magnetization, down to the bilayer limit. Given the versatility of vdW heterostructures, these coherent 2D magnons may be basis for optically accessible magnonics and quantum interconnects.Comment: 14 pages, 5 figures, 30 pages Supporting Inf

Inhibitors of plasmodial serine hydroxymethyltransferase (SHMT) : co-crystal structures of pyrazolopyrans with potent blood-and liver-stage activities

Several of the enzymes related to the folate cycle are well-known for their role as clinically validated antimalarial targets. Nevertheless for serine hydroxymethyltransferase (SHMT), one of the key enzymes of this cycle, efficient inhibitors have not been described so far. On the basis of plant SHMT inhibitors from an herbicide optimization program, highly potent inhibitors of Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) SHMT with a pyrazolopyran core structure were identified. Cocrystal structures of potent inhibitors with PvSHMT were solved at 2.6 A resolution. These ligands showed activity (IC50/EC50 values) in the nanomolar range against purified PfSHMT, blood-stage Pf, and liver-stage P. berghei (Pb) cells and a high selectivity when assayed against mammalian cell lines. Pharmacokinetic limitations are the most plausible explanation for lack of significant activity of the inhibitors in the in vivo Pb mouse malaria mode

Spontaneous Assembly Of A Hinged Coordination Network

THE field of supramolecular chemistry has advanced to a stage at which it is possible to select building blocks that will self-assemble into structures with specific network topologies(1-3). This makes possible the rational design and synthesis of molecular solids with potentially interesting properties. Here we report the construction of open, hinged networks from molecular building blocks, This class of materials has been predicted to exhibit unusual mechanical properties, including auxetic behaviour (negative Poisson's ratio) and negative coefficients of thermal expansion(4-6). Our approach relies on the notion that rigid organic molecules of high symmetry will adopt one of only a few possible structures when linked via hydrogen bonds or coordination to metals(7-9). We use trigonal ligands to make networks joined at the vertices by metal ions; the resulting networks are homeotypic(10) with the honeycomb-like AIB(2) and the hinge-like ThSi2 phases. The hinge-like network has channels of inner diameter 15 Angstrom, within which included molecules can be exchanged while the framework remains intact, We have not yet determined whether this material is auxetic.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62644/1/374792a0.pd

Social micro-siting : increasing acceptance through local adaption

The establishment of land-based wind-farms often requires large land areas affecting a number of contradictory interests including the individual interests of citizens. In Sweden consultation is statutory, prescribed by Swedish Environmental Code including all individuals affected by the project. Projectors often invite to consultative process in a stage where the project has made some progress and where a site-plan is more or less established. From the citizen perspective, wind farm projects affecting the local area might seem threatening. For instance, for people living in rural areas, the characteristics of the surrounding environment are closely connected to their way of life. Thereby, “threats” towards the local environment might pose a threat to their entire outlook on life. Often this leads to frustration and rage towards the projector. This presentation introduces the basic features of a consultative process more thoroughly involving and adjusting to citizens and their local community and the distinguishing characteristics of their local physical and social environment, Social Micro-Siting. Social Micro-Siting has the potential to create added value to the participating community and to the projector, increasing the general acceptance of wind-farm localization. As the process is based on ongoing dialogue with the local citizens, it might also provide solutions to complex local issues of a more practical character.Godkänd; 2012; 20121218 (andbra)</p