Download Diamond Quantum Magnetomets

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
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NV- and NV0 luminescence can be switched at the surface interaction
with charge (DNA)-> probes/sensors ?
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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