30 research outputs found
Identification of charge separated states in thymine single strands
UV excitation of the DNA single strand (dT)(18) leads to electronically excited states that are potential gateways to DNA photolesions. Using time-resolved infrared spectroscopy we characterized a species with a lifetime of similar to 100 ps and identified it as a charge separated excited state between two thymine bases
Identification of charge separated states in thymine single strands
UV excitation of the DNA single strand (dT)(18) leads to electronically excited states that are potential gateways to DNA photolesions. Using time-resolved infrared spectroscopy we characterized a species with a lifetime of similar to 100 ps and identified it as a charge separated excited state between two thymine bases
Extending the coherence time of spin defects in hBN enables advanced qubit control and quantum sensing
Spin defects in hexagonal Boron Nitride (hBN) attract increasing interest for
quantum technology since they represent optically-addressable qubits in a van
der Waals material. In particular, negatively-charged boron vacancy centers
() in hBN have shown promise as sensors of temperature, pressure, and
static magnetic fields. However, the short spin coherence time of this defect
currently limits its scope for quantum technology. Here, we apply dynamical
decoupling techniques to suppress magnetic noise and extend the spin coherence
time by nearly two orders of magnitude, approaching the fundamental
relaxation limit. Based on this improvement, we demonstrate advanced spin
control and a set of quantum sensing protocols to detect electromagnetic
signals in the MHz range with sub-Hz resolution. This work lays the foundation
for nanoscale sensing using spin defects in an exfoliable material and opens a
promising path to quantum sensors and quantum networks integrated into
ultra-thin structures
TRY plant trait database â enhanced coverage and open access
Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Advances in nano- and microscale NMR spectroscopy using diamond quantum sensors
Quantum technologies have seen a rapid developmental surge over the last couple of years. Though often overshadowed by quantum computation, quantum sensors show tremendous potential for widespread applications in chemistry and biology. One system stands out in particular: the nitrogen-vacancy (NV) center in diamond, an atomic-sized sensor allowing the detection of nuclear magnetic resonance (NMR) signals at unprecedented length scales down to a single proton. In this article, we review the fundamentals of NV center-based quantum sensing and its distinct impact on nano- to microscale NMR spectroscopy. Furthermore, we highlight and discuss possible future applications of this novel technology ranging from energy research, material science, or single-cell biology, but also associated challenges of these rapidly developing NMR sensors
Advances in nano- and microscale NMR spectroscopy using diamond quantum sensors
Quantum technologies have seen a rapid developmental surge over the last
couple of years. Though often overshadowed by quantum computation, quantum
sensors show tremendous potential for widespread applications in chemistry and
biology. One system stands out in particular: the nitrogen-vacancy (NV) center
in diamond, an atomic-sized sensor allowing the detection of nuclear magnetic
resonance (NMR) signals at unprecedented length scales down to a single proton.
In this article, we review the fundamentals of NV center-based quantum sensing
and its distinct impact on nano- to microscale NMR spectroscopy. Furthermore,
we highlight and discuss possible future applications of this novel technology
ranging from energy research, material science, or single-cell biology, but
also associated challenges of these rapidly developing NMR sensors.Comment: 42 pages, 6 figures, 2 table
Hyperpolarization-Enhanced NMR Spectroscopy with Femtomole Sensitivity Using Quantum Defects in Diamond
Nuclear magnetic resonance (NMR) spectroscopy is a widely used tool for chemical analysis and molecular structure identification. Because it typically relies on the weak magnetic fields produced by a small thermal nuclear spin polarization, NMR suffers from poor molecule-number sensitivity compared to other analytical techniques. Recently, a new class of NMR sensors based on optically probed nitrogen-vacancy (NV) quantum defects in diamond have allowed molecular spectroscopy from sample volumes several orders of magnitude smaller than the most sensitive inductive detectors. To date, however, NV NMR spectrometers have only been able to observe signals from pure, highly concentrated samples. To overcome this limitation, we introduce a technique that combines picoliter-scale NV NMR with fully integrated Overhauser dynamic nuclear polarization to perform high-resolution spectroscopy on a variety of small molecules in dilute solution, with femtomole sensitivity. Our technique advances the state of the art of mass-limited NMR spectroscopy, opening the door to new applications at the picoliter scale in drug and natural-product discovery, catalysis research, and single-cell studies