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some particle is determined, the less precisely its momentum can be kn Optical relatingQuantum the standard deviation of position σ x and the standard deviation [3] later that Sensors foryearBiology Kennard and by Hermann Weyl[4] in 1928: (ħ is the reduced Planck constant, h / 2π). Historically, the uncertainty principle has been confused[5][6] with a som …. ipseeffect, se nihil scirenotes id unum sciat (Socrates) observer which that measurements of certain systems cann Heisenberg offered such an observer effect at the quantum level (see be uncertainty.[7] It has since become clear, however, that the uncertainty p like systems,[8] and that it arises in quantum mechanics simply due to t Principles Spin in diamond and bond orbitals are split into one low-energy symmet ric a1 (1 a1(2), ex and ey [3]. Two out of t he six elect rons occupy sit t ing below t he edge of t he valence band. The four o over t he t hree levels a1(2), ex and ey (see Fig. 2.2b). Spin Resonance Figure 2.2: Electronic st ructure of t he NV − cent re. (a) molecular orbit als1 . (b) Simplified schematic v tion of the ground and excited state (ms = 1) t he NV − in diamond2 . In addit ion, energy v insert ed and depicted in blue with st ars. 1 of t he NV’s Figure 2.2a1 illust rat es t he wave funct±ions corresponding t o positive (negative) cont ribut ions, respe level diagram of NV − and includes detailed energy leve calculat ed from density funct ional t heory [6]. The energy The presence of an external magnetic field induces a splittin DIAMOND Principle (Zeeman effect) (Figure 2b), resulting in a splitting between th Zeeman Splitting From this effect, it is possible to determine the magnitude promoting electrons from the ground to excited state in the NV center. The radiative decay of equation (eq.1): these electrons (to the ground state) induces the emission of red light. The photo-luminescent (optical) transitions associated with the spin sublevels of NV ground state present different B electrons 0 brightness. The application of a microwave field with resonant frequency drives from the |0> to the |±1> spin sublevels, and leads therefore to a drop of the luminescence intensity. Microwave energy ms = +-1 ΔE=gμ B , where g is the electronic g factor (~2 for NV center), μB is a ms = 0 magnetic field to be measured. The sensitivity at which the r ν=ΔE/h can be determined is given by (eq. 2) [3] η~πħ/(2gμB C √(T2 where η is the magnetic field sensitivity, C is a constant de m =0 s Spin physics ations of the special relativity theory". Resonance Magnetic (MRI, ESR) l relativity, and this connection between spin and [6] just like a mics. These ral ways, etic fields tic fields h charge tor. For he mass es a ory of lectron ghe value noting ard Schematic diagram depicting the spin of the neutron as the black arrow and Magnetfeld: 0-4T magnetic field lines associated with Frequenzen: Hz-200MHz / the neutron magnetic moment. The FM-Radio: 100MHz; m neutron has a negative magnetic moment. While the spin of the neutron is upward in this diagram, the magnetic field lines at the center of the dipole are downward. GHz DIPOLE IN MAGNETIC FIELD - NUCLEAR SPIN - ELECTRON SPINS HOW DOES IT WORK ?NCE EXCITATIO N LUMINESCENCE EXCITATIO N LUMINESCEN CE NV produces photo-stable near IR luminescence with single photon generation! N ELECTRONIC STRUCTURE V N V N ELECTRONIC STRUCTURE V EXCITED STATE N V 532 nm 637 nm GROUN D STATE DARK TRANSI TION N ELECTRONIC STRUCTURE V EXCITED STATE N V 532 nm DARK TRANSI TION 637 nm ms = ±1 ~ D = 2,87 GHz GROUN D STATE ms = N ELECTRONIC STRUCTURE V EXCITED STATE N V 532 nm DARK TRANSI TION 637 nm ms = ±1 ~ D = 2,87 GHz GROUN D STATE ms = N ELECTRONIC STRUCTURE V EXCITED STATE N V 532 nm DARK TRANSI TION 637 nm ms = +1 ms = ±1 ~ Δ=γ. B ~ D = 2,87 GHz GROUN D STATE ms = ms = 1 ~ ω=D½Δ ms = N ELECTRONIC STRUCTURE V EXCITED STATE N V 532 nm DARK TRANSI TION 637 nm ms = +1 ms = ±1 ~ Δ=γ. B ~ D = 2,87 GHz GROUN D STATE ms = ms = 1 ~ ω=D½Δ ms = Standard quantum sensitivity limit Bohr magne From Wikipedia, the free e In atomic physics, the Bo a physical constant and t the magnetic moment of its orbital or spin angular Ground-state gyromagnetic ratio The Bohr magneton is de Number of atoms Spin-relaxation time Measurement time 13 Diamant Magnetometer Ein neuer Sensor nutzt einzelne Atome um Magnetfelder mit einer sehr hohen Ortstauflösung zu messen Diamantsensor Magnetische Wechselwirkung B 0 e r 3 1 3 cos ( )S 2 DNA-Molekül Spin Distance (r) 455, Field Balasubramanian, G. et. Nature 648-651 Electron 10 nm 1µT (2008). Proton 10 nm 1nT Required T2 ~ 2 µs ~ 2 ms z Sensing Magnetic fields : from compass to reading minds 1 T = N/A m = kg/ C sec 20 – 50 micro T - - - > 50 fT Photonics and Nanofabrication M. Nesladek, E. Bourgeois [email protected] Atomic scale technologies – NV diamond ma Atomic scale processors Scanning probe magnetomet er Biosensing e.g. ion channels Quantum photonics Optical sensing at nanoscale NV -Color centers in diamond: Action potential imaging in neural synapses Problems: Low magnetic fields – pT, temporary detection – msec, no subtreshold signals L.T.Hall et al, Scientific Reports, 2012 Magnetic Resonance Imaging in Cells spectrum 970000 Fluor. a. u. 965000 960000 955000 950000 945000 940000 2,70 2,75 2,80 2,85 2,90 MW Frequency, GHz MR possible through cell cultures, Development of diagnostic structure -> Single digit nanodiamond to pass Blood Brain Barrier (BBB) -> Readout in Near Infrared Window -> DNP MR NV spin centre Readout 2,95 3,00 Ultimate single molecule bio-sensors – Magnetic and electric requires closer proximity to the surface and dedicated decoupling techniques to measure a 3 nuclear magnetic resonance signal. Initial demonstrations have shown NMR from (5 nm) volumes e containing 104 nuclear spins [8,9]. By reducing the distance to the surface to around 2 nm the sensitivity could be reduced to around 5 nuclear spins [10]. It is to be expected that this value will be reduced to single nuclear spins soon. Brain – Machine Interfaces • • • • • Sensitivity scaling with 𝑡 Sensitivity 𝟎.𝟗𝐩𝐓/ 𝐇𝐳 100 fT absolute Or ~ 10nT/ Hz∙μm2 Sensor Volume: V = 8.5·10-4 mm3 T. Wolf et al., Phys. Rev. X 5, 041001 (2015) • 40 fT/ Hz with 𝑇𝜑 = 2 ms via decoupling (up to T1-limit at RT (already shown) • 9fT/ Hz(spinprojectionnoiselimit) Trackers for cell biology 21 In-cell ND tracking nanoprobes based on NV PL INTRODUCTION NV Chang Nature Nanotech. 2008 Gruber A, Science, 276, 1997 Transfection ( DNA) and biomolecular sensing A polymeric transfection enzyme – positively charged, polyethylenimine (PEI) condenses DNA onto positively charged particles, binds to anionic cell surface residues and are brought into the cell via endocytosis. Fluorescent Nanodiamond 1.#Concept#of# oflur escent#nanod WP2$ # - - --- Can#om or#hyb - ,$ $ $F.$Schmidt@ Kaler,$K $ $$ $ NV- and NV0 luminescence can be switched at the surface interaction with charge (DNA)-> probes/sensors ? @ Biocompa: bility# @ C<#Surface#Chemistry#(covalent,#non#covale @ Stable#NV#center#fluorescence## TexPoint$fonts$used$in$EMF.$$ Read$the$TexPoint$manual$before$you$delete$this$box.: Luminiscence for NV0 and NV- centre originating from nanodiamond MgGuinness et al, Nature Nanotech, 2011 Applications of Carcinoma Cells To estimate the NV density within the spots the fluorescent NV containing NDs deposed on the substrate had been used to estimate the fluorescence intensity for a single NV ( time coherence anti-bunching experiments). “x”: number of NVs 19 33 54 49 52 kcps equals one NV for the same experimental conditions. The number of NVs per spot had been marked in the right image (blue numbers) 24 20 22 86 FP7 Dinamo in preparation for publication