Nanoscopic thermal and magnetic field detectors - which can be inserted into living cells - could enhance our understanding of everything from chemical reactions within single cells to signalling in neural networks and the origin of magnetism in novel materials.
This image shows nanodiamonds.
Credit: H.S Knowles and C.H.H Schulte
Atomic impurities in natural diamond structure give rise to the colour seen in rare and coveted pink, blue and yellow diamond. But these impurities are also a major research focus in emerging areas of quantum physics.
One such defect, the Nitrogen-vacancy Centre (NVC), consists of a gap in the crystal lattice next to a nitrogen atom. This system tightly traps electrons whose spin states can be manipulated with extreme precision.
Electron coherence - the extent to which the spins of these particles can sustain their quantum mechanical properties - has been achieved to high levels in the NVCs of large 'bulk' diamonds, with coherence times of an entire second in certain conditions - the longest yet seen in any solid material.
However in nanodiamonds - nanometer sized crystals that can be produced by milling conventional diamond - any acceptable degree of coherence has, until now, proved elusive.
Nanodiamonds offer the potential for both extraordinarily precise resolution, as they can be positioned at the nano-scale, and biocompatibility - as they have can be inserted into living cells. But without high levels of coherence in their NVCs to carry information, these unique nanodiamond benefits cannot be utilised.
By observing the spin dynamics in nanodiamond NVCs, researchers at Cambridge's Cavendish Laboratory, have now identified that it is the concentration of nitrogen impurities that impacts coherence rather than interactions with spins on the crystal surface.
By controlling the dynamics of these nitrogen impurities separately, they have increased NVC coherence times to a record 0.07 milliseconds longer than any previous report, an order of significant magnitude - putting nanodiamonds back in play as an extremely promising material for quantum sensing.
The results are published today in the journal Nature Materials.
"Our results unleash the potential of the smallest magnetic field and temperature detector in the world. Nanodiamond NVCs can sense the change of such features within a few tens of nanometres - no other sensor has ever had this spatial resolution under ambient conditions," said Helena Knowles, a researcher on the study.
"We now have both high spin coherence and spatial resolution, crucial for various quantum technologies."
Dr Dhiren Kara, who also worked on the study, points out that the nanodiamond's biocompatibility can provide non-invasive optical access to magnetic changes within a living cell - essentially the ability to perform MRI and detect, for instance, a cell's reaction to a drug in real time.
"We may also be able to answer some key questions in material science, such as magnetic ordering at the edges of graphene or the origin of magnetism in oxide materials," Kara said.
Dr Mete Atature, director of the research, added: "The pursuit of simultaneous high NVC coherence and high spatial resolution, and the fact that nanodiamonds couldn't deliver on this promise until now, has required researchers to invest in alternative means including advanced nanofabrication techniques, which tends to be both expensive and low-yield."
"The simplest solution - feasible and inexpensive - was in front of us the whole time."
Dr. Mete Atature | EurekAlert!
Research finds new molecular structures in boron-based nanoclusters
13.07.2018 | Brown University
3D-Printing: Support structures to prevent vibrations in post-processing of thin-walled parts
12.07.2018 | Fraunhofer-Institut für Produktionstechnologie IPT
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences