ORCID Profile
0000-0001-6061-7537
Current Organisations
University of Turin
,
University of Melbourne
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Nanomaterials | Condensed Matter Physics | Electronic and Magnetic Properties of Condensed Matter; Superconductivity
Expanding Knowledge in the Physical Sciences | Emerging Defence Technologies | Scientific Instruments |
Publisher: American Physical Society (APS)
Date: 29-01-2019
Publisher: Research Square Platform LLC
Date: 30-11-2021
DOI: 10.21203/RS.3.RS-1069506/V1
Abstract: Controlling and manipulating in idual quantum systems in solids underpins the growing interest in development of scalable quantum technologies 1, 2 . Recently, hexagonal boron nitride (hBN) has garnered significant attention in quantum photonic applications due to its ability to host optically stable quantum emitters 3-7 . However, the large band gap of hBN and the lack of efficient doping inhibits electrical triggering and limits opportunities to study electrical control of emitters. Here, we show an approach to electrically modulate quantum emitters in an hBN–graphene van der Waals heterostructure. We show that quantum emitters in hBN can be reversibly activated and modulated by applying a bias across the device. Notably, a significant number of quantum emitters are intrinsically dark, and become optically active at non-zero voltages. To explain the results, we provide a heuristic electrostatic model of this unique behaviour. Finally, employing these devices we demonstrate a nearly-coherent source with linewidths of ~ 160 MHz. Our results enhance the potential of hBN for tunable solid state quantum emitters for the growing field of quantum information science.
Publisher: MDPI AG
Date: 23-04-2018
DOI: 10.3390/S18041290
Publisher: AIP Publishing
Date: 30-07-2012
DOI: 10.1063/1.4742736
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-04-2017
Abstract: We demonstrate diamond-based quantum imaging of the current flow in graphene structures with submicrometer resolution.
Publisher: AIP Publishing
Date: 05-10-2020
DOI: 10.1063/5.0026104
Abstract: Surfaces and interfaces can dominate charge carrier transport dynamics in electronic devices, impeding realization of a material's full potential. Here, we investigate transport in a two-terminal diamond device comprising a conductive channel defined by a hydrogen-terminated diamond surface, bridging two TiC contacts. The surface charge distribution was imaged by monitoring the photoluminescence of nitrogen vacancy centers incorporated below the active device layer. A strong charge accumulation near the TiC contact/H-terminated channel interface is observed and is discussed in terms of deviation from Ohmic behavior evident in the DC electrical measurements. Small voltage steps applied to the device result in current transients due to carrier trapping at the contact/diamond interface. This gives rise to dynamic negative capacitance at low AC frequencies and is discussed in detail.
Publisher: Wiley
Date: 03-12-2018
Publisher: Elsevier BV
Date: 06-2022
Publisher: AIP Publishing
Date: 08-10-2021
DOI: 10.1063/5.0055100
Abstract: Color centers that emit light at telecommunication wavelengths are promising candidates for future quantum technologies. A pressing challenge for the broad use of these color centers is the typically low collection efficiency from bulk s les. Here, we demonstrate enhancements of the emission collection efficiency for Er3+ incorporated into 4H-SiC surface nano-pillars fabricated using a scalable top-down approach. Optimal Er ion implantation and annealing strategies are investigated in detail. The substitutional fraction of Er atoms in the SiC lattice is closely correlated with the peak photoluminescence intensity. This intensity is further enhanced via spatial wave-guiding once the surface is patterned with nano-pillars. These results have broad applicability for use with other color centers in SiC and also demonstrate a step toward a scalable protocol for fabricating photonic quantum devices with enhanced emission characteristics.
Publisher: American Chemical Society (ACS)
Date: 04-02-2020
Publisher: American Physical Society (APS)
Date: 26-08-2020
Publisher: Springer Science and Business Media LLC
Date: 18-07-2022
Publisher: Springer Science and Business Media LLC
Date: 06-2015
Publisher: American Physical Society (APS)
Date: 26-09-2019
Publisher: Wiley
Date: 23-08-2020
Publisher: American Physical Society (APS)
Date: 08-11-2018
Publisher: American Physical Society (APS)
Date: 09-08-2019
Publisher: American Physical Society (APS)
Date: 02-02-2018
Publisher: Springer Science and Business Media LLC
Date: 08-09-2022
Publisher: Research Square Platform LLC
Date: 11-05-2022
DOI: 10.21203/RS.3.RS-1102242/V1
Abstract: Technologies that capture the complex electrical dynamics occurring in biological systems, across fluid membranes and at solid-liquid interfaces drive fundamental understanding and innovation in erse fields from neuroscience to energy storage. However, the capabilities of existing voltage imaging techniques utilizing micro-electrode arrays, scanning probes, or optical fluorescence methods are respectively limited by resolution, scan speed, and photostability. Here we develop an optoelectronic voltage imaging system which overcomes these limitations by using charge-sensitive fluorescent reporters embedded within a transparent semiconducting diamond device. Electrochemical tuning of the diamond surface termination enables photostable optical voltage imaging with a quantitative linear response at biologically relevant voltages and timescales. This technology represents a major step toward label-free, large-scale, and long-term voltage recording of physical and biological systems with sub-micron resolution.
Publisher: AIP Publishing
Date: 18-02-2020
DOI: 10.1063/1.5144093
Abstract: We report the preparation of a silicon terminated (111) diamond surface. Low energy electron diffraction and core level photoemission demonstrate that this surface is highly ordered and homogeneous and possesses a negative electron affinity. Our analysis suggests that the surface reconstruction begins with the formation of silicon trimers that coalesce into a rhombohedral 2D silicon layer reminiscent of rhombohedral silicene.
Publisher: American Chemical Society (ACS)
Date: 31-05-2019
DOI: 10.1021/ACS.NANOLETT.9B01402
Abstract: The precise measurement of mechanical stress at the nanoscale is of fundamental and technological importance. In principle, all six independent variables of the stress tensor, which describe the direction and magnitude of compression/tension and shear stress in a solid, can be exploited to tune or enhance the properties of materials and devices. However, existing techniques to probe the local stress are generally incapable of measuring the entire stress tensor. Here, we make use of an ensemble of atomic-sized in situ strain sensors in diamond (nitrogen-vacancy defects) to achieve spatial mapping of the full stress tensor, with a submicrometer spatial resolution and a sensitivity of the order of 1 MPa (10 MPa) for the shear (axial) stress components. To illustrate the effectiveness and versatility of the technique, we apply it to a broad range of experimental situations, including mapping the stress induced by localized implantation damage, nanoindents, and scratches. In addition, we observe surprisingly large stress contributions from functional electronic devices fabricated on the diamond and also demonstrate sensitivity to deformations of materials in contact with the diamond. Our technique could enable in situ measurements of the mechanical response of diamond nanostructures under various stimuli, with potential applications in strain engineering for diamond-based quantum technologies and in nanomechanical sensing for on-chip mass spectroscopy.
Publisher: Springer Science and Business Media LLC
Date: 13-09-2018
Publisher: American Chemical Society (ACS)
Date: 12-06-2020
Publisher: IOP Publishing
Date: 30-10-2023
Publisher: American Chemical Society (ACS)
Date: 26-02-2020
Publisher: Springer Science and Business Media LLC
Date: 20-06-2022
DOI: 10.1038/S41377-022-00877-7
Abstract: Controlling and manipulating in idual quantum systems in solids underpins the growing interest in the development of scalable quantum technologies. Recently, hexagonal boron nitride (hBN) has garnered significant attention in quantum photonic applications due to its ability to host optically stable quantum emitters. However, the large bandgap of hBN and the lack of efficient doping inhibits electrical triggering and limits opportunities to study the electrical control of emitters. Here, we show an approach to electrically modulate quantum emitters in an hBN-graphene van der Waals heterostructure. We show that quantum emitters in hBN can be reversibly activated and modulated by applying a bias across the device. Notably, a significant number of quantum emitters are intrinsically dark and become optically active at non-zero voltages. To explain the results, we provide a heuristic electrostatic model of this unique behavior. Finally, employing these devices we demonstrate a nearly-coherent source with linewidths of ~160 MHz. Our results enhance the potential of hBN for tunable solid-state quantum emitters for the growing field of quantum information science.
Publisher: AIP Publishing
Date: 05-03-2018
DOI: 10.1063/1.5021491
Abstract: Precise control of the resonant frequency of a spin qubit is of fundamental importance to quantum sensing protocols. We demonstrate a control technique on a single nitrogen-vacancy (NV) centre in diamond where the applied magnetic field is modified by fine-tuning a permanent magnet's magnetisation via temperature control. Through this control mechanism, nanoscale cross-relaxation spectroscopy of both electron and nuclear spins in the vicinity of the NV centre is performed. We then show that through maintaining the magnet at a constant temperature, an order of magnitude improvement in the stability of the NV qubit frequency can be achieved. This improved stability is tested in the polarisation of a small ensemble of nearby 13C spins via resonant cross-relaxation, and the lifetime of this polarisation explored. The effectiveness and relative simplicity of this technique may find use in the realisation of portable spectroscopy and/or hyperpolarisation systems.
Publisher: American Chemical Society (ACS)
Date: 26-06-2013
DOI: 10.1021/CG400383T
Publisher: MDPI AG
Date: 07-02-2020
DOI: 10.3390/C6010007
Abstract: Hydrogenated detonation nanodiamonds are of great interest for emerging applications in areas from biology and medicine to lubrication. Here, we compare the two main hydrogenation techniques—annealing in hydrogen and plasma-assisted hydrogenation—for the creation of detonation nanodiamonds with a hydrogen terminated surface from the same starting material. Synchrotron-based soft X-ray spectroscopy, infrared absorption spectroscopy, and electron energy loss spectroscopy were employed to quantify diamond and non-diamond carbon contents and determine the surface chemistries of all s les. Dynamic light scattering was used to study the particles’ colloidal properties in water. For the first time, steady-state and time-resolved fluorescence spectroscopy analysis at temperatures from room temperature down to 10 K was performed to investigate the particles’ fluorescence properties. Our results show that both hydrogenation techniques produce hydrogenated detonation nanodiamonds with overall similar physico-chemical and fluorescence properties.
Publisher: AIP Publishing
Date: 20-12-2021
DOI: 10.1063/5.0073320
Abstract: The widefield diamond nitrogen-vacancy (NV) microscope is a powerful instrument for imaging magnetic fields. However, a key limitation impeding its wider adoption is its complex operation, in part due to the difficulty of precisely interfacing the sensor and s le to achieve optimum spatial resolution. Here, we demonstrate a solution to this interfacing problem that is practical and reliably minimizes NV-s le standoff. We built a compact widefield NV microscope, which incorporates an integrated widefield diamond probe with full position and angular control, and developed a systematic alignment procedure based on optical interference fringes. Using this platform, we imaged an ultrathin (1 nm) magnetic film test s le and conducted a detailed study of the spatial resolution. We reproducibly achieved an estimated NV-s le standoff (and hence spatial resolution) of at most ∼2 μm across a ∼0.5 mm field of view. Guided by these results, we suggest future improvements for approaching the optical diffraction limit. This work is a step toward realizing a widefield NV microscope suitable for routine high-throughput mapping of magnetic fields.
Publisher: American Chemical Society (ACS)
Date: 22-07-2022
Abstract: Interest in van der Waals materials often stems from a desire to miniaturize existing technologies by exploiting their intrinsic layered structures to create near-atomically thin components that do not suffer from surface defects. One appealing property is an easily switchable yet robust magnetic order, which is only sparsely demonstrated in the case of in-plane anisotropy. In this work, we use widefield nitrogen-vacancy (NV) center magnetic imaging to measure the properties of in idual flakes of CuCrP
Start Date: 2022
End Date: 2024
Funder: Australian Research Council
View Funded ActivityStart Date: 11-2022
End Date: 11-2025
Amount: $400,000.00
Funder: Australian Research Council
View Funded Activity