Fast nanoscale addressability of individual NV spins via...
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Michael Wolf, Robert Badea and Jesse Berezovsky Physics Department, Case Western Reserve University, Cleveland, OH 44106 We acknowledge DOE, grant No. DE-SC0008148 Fast nanoscale addressability of individual NV spins via coupling to driven ferromagnetic vortices Reflectance 2 μm Introduction • Diamond nanoparticles with NVs are dispersed on a gold coplanar waveguide (CPW) with fabricated ferromagnetic disks. • A scanning microscopy set-up is used to initialize and detect NV spins and image magnetization. • The disk is magnetized in a single vortex domain. • The vortex core position is controlled by an applied magnetic field. • See poster on Wednesday for more detail. Magnetization maps • B CPW is capable of translating the vortex within tens of ns over several hundreds of nm. • Vortex magnetic field near the surface of the disk can reach several hundred mT. ODMR (a.u.) 1 0.85 0 2 4 6 8 10 B x (mT) Microwave field enhancement B x = 0 mT B x = 5 mT B x = 9 mT X Y MOKE Laser Spec. EMCCD AOM PMT PMT TCSPC 2.5 μm 2.5 μm 20 μm 20 μm Permalloy disk Diamond nanoparticle with several NVs B CPW Gold CPW X Y Photoluminescence (a.u.) 2.8 3 3.2 • Simulated ODMR of two NVs coupled to vortex. • NVs 10 nm apart, 20 nm above vortex. • Significant splitting between the two NVs. 0 100 200 300 MW pulse length (ns) 1 0.93 0.96 Rel. PL (a.u.) Laser CPW MW • Rabi oscillations are measured by varying the MW pulse length with constant B CPW . • Large enhancement of the Rabi frequency at some vortex positions. • Enhancement largest with vortex close to NVs. 0 2 -2 B x (mT) Rabi Frequency enhancement Fast NV addressability • Spin rotated to B1 direction via adiabatic passage • Relaxation into resonance with MW field yields high fidelity π/2 rotation (‘adiabatic half passage’). • AHP aligns spin with MW field in the rotating frame (B1). • Subsequent manipulation possible with phase- shifted MW field (B1’ in the rotating frame). B1 B1’ S Ferromagnetic vortex domains produce strong, localized, rapidly- tunable magnetic fields which may be useful for nanoscale spintronic or quantum information processing devices. A vortex interacting with adjacent NV spins provides a platform for addressing individual spins for coherent manipulation or coupling. Here, we show that this interaction leads to large spin splitting, enhancement of microwave fields and spin manipulation via adiabatic passage. Magneto-optical Kerr effect Experimental set-up Vortex-induced spin splitting 2.6 1 -1 0 0 150 300 450 CPW pulse length (ns) Spin projection Micromagnetic OOMMF simulation Frequency (GHz) Vortex path NVs • Sweep vortex past nanoparticle with several NVs. • Monitor NV spin spitting via optically detected magnetic resonance (ODMR). • Large splitting when vortex is near NVs. • Broadening caused by vortex induced MW field enhancement. • Jumps occur to vortex pinning (see poster on Wednesday). B AC = 175 μT 2.6 2.8 3 3.2 Frequency (GHz) 0 2 4 6 8 10 B x (mT) No vortex • At B 1 NV1 is in resonance with f MW • At B 2 NV2 is in resonance with f MW • At B 12 NV1 and NV2 are in resonance with each other but not with f MW . Pulsing between B 1, B 2, and B 12 allows operations on NV1 and NV2. B CPW (mT) 2 1 -1 -2 0 2.6 2.8 3 3.2 Frequency (GHz) NV1 NV2 B 2 B 12 B 1 f MW B AC = 15 μT B CPW (mT) 2 1 -1 -2 0 2.6 2.8 3 3.2 Frequency (GHz) B x = 2 mT Vortex path NVs Laser CPW MW MW pulse length (ns) 0 150 300 Rel. PL (a.u.) B AC = 500 μT Pulse the vortex position to bring a particular NV into resonance. Method 1: Move vortex then manipulate spin Method 2: Move vortex while manipulating spin (adiabatic passage) 0 100 200 300 MW pulse length (ns) 1 0.96 Rel. PL (a.u.) 0.92 0.98 0.94 Laser CPW MW • Confirmed coherence by observing Rabi oscillations about B1’ AHP to B1 Rabi about B1’ Laser CPW B1 B1’ 0 100 200 300 MW pulse length (ns) 1 0.96 Rel. PL (a.u.) 0.92 0.98 0.94 • Vortex relaxes after voltage step in ≈100ns. • MW pulse begins 100ns after CPW step. • Minimal reduction in oscillation amplitude. -2 0 2 4 30 0 Vortex position MOKE 0 B y (mT)
Transcript of Fast nanoscale addressability of individual NV spins via...
Michael Wolf, Robert Badea and Jesse Berezovsky
Physics Department, Case Western Reserve University, Cleveland, OH 44106
We acknowledge DOE, grant No. DE-SC0008148
Fast nanoscale addressability of individual NV spins via coupling to
driven ferromagnetic vortices
Reflectance
2 μm
Introduction
• Diamond nanoparticles with NVs are dispersed on a gold coplanar waveguide
(CPW) with fabricated ferromagnetic disks.
• A scanning microscopy set-up is used to initialize and detect NV spins and
image magnetization.
• The disk is magnetized in a single vortex domain.
• The vortex core position is controlled by an applied magnetic field.
• See poster on Wednesday for more detail.
Magnetization maps
• BCPW is capable of translating the
vortex within tens of ns over several
hundreds of nm.
• Vortex magnetic field near the
surface of the disk can reach several
hundred mT.
OD
MR
(a.u
.)
1
0.85
0
2
4
6
8
10 B
x (
mT
)
Microwave field enhancement
Bx = 0 mT Bx = 5 mT Bx = 9 mT X
Y
MOKE
Laser
Spec. EMCCD
AOM
PM
T
PMT
TCSPC
2.5
μm
2.5 μm 20 μm
20
μm
Permalloy disk
Diamond nanoparticle
with several NVs
BCPW
Gold CPW
X
Y
Ph
oto
lum
inescen
ce (
a.u
.)
2.8 3 3.2
• Simulated ODMR of two NVs
coupled to vortex.
• NVs 10 nm apart, 20 nm
above vortex.
• Significant splitting between
the two NVs.
0 100 200 300 MW pulse length (ns)
1
0.93
0.96
Re
l. P
L (
a.u
.)
Laser
CPW
MW
• Rabi oscillations are measured by varying the MW
pulse length with constant BCPW.
• Large enhancement of the Rabi frequency at some
vortex positions.
• Enhancement largest with vortex close to NVs.
0 2 -2
Bx (m
T)
Rab
i F
req
ue
ncy
enh
an
cem
ent
Fast NV addressability
• Spin rotated to B1 direction
via adiabatic passage
• Relaxation into resonance with MW field yields
high fidelity π/2 rotation (‘adiabatic half
passage’).
• AHP aligns spin with MW field in the rotating
frame (B1).
• Subsequent manipulation possible with phase-
shifted MW field (B1’ in the rotating frame). B1 B1’
S
Ferromagnetic vortex domains produce strong, localized, rapidly-
tunable magnetic fields which may be useful for nanoscale spintronic or
quantum information processing devices. A vortex interacting with
adjacent NV spins provides a platform for addressing individual spins
for coherent manipulation or coupling. Here, we show that this
interaction leads to large spin splitting, enhancement of microwave
fields and spin manipulation via adiabatic passage.
Magneto-optical Kerr effect
Experimental set-up
Vortex-induced spin splitting
2.6
1
-1
0
0 150 300 450
CPW pulse length (ns)
Spin
pro
jection
Micromagnetic OOMMF simulation
Frequency (GHz)
Vortex
path NVs
• Sweep vortex past
nanoparticle with several
NVs.
• Monitor NV spin spitting via
optically detected magnetic
resonance (ODMR).
• Large splitting when vortex
is near NVs.
• Broadening caused by
vortex induced MW field
enhancement.
• Jumps occur to vortex
pinning (see poster on
Wednesday).
BAC = 175 μT
2.6 2.8 3 3.2
Frequency (GHz)
0
2
4
6
8
10
Bx (
mT
)
No vortex
• At B1 NV1 is in resonance with fMW
• At B2 NV2 is in resonance with fMW
• At B12 NV1 and NV2 are in
resonance with each other but not
with fMW.
Pulsing between B1, B2,
and B12 allows operations
on NV1 and NV2.
BC
PW
(mT
)
2
1
-1
-2
0
2.6 2.8 3 3.2
Frequency (GHz)
NV1
NV2
B2
B12
B1
fMW
BAC = 15 μT
BC
PW
(mT
)
2
1
-1
-2
0
2.6 2.8 3 3.2 Frequency (GHz)
Bx = 2 mT
Vortex
path NVs
Laser
CPW
MW
MW pulse length (ns) 0 150 300
Re
l. P
L (
a.u
.)
BAC= 500 μT
Pulse the vortex position to bring a
particular NV into resonance.
Method 1: Move vortex then manipulate spin
Method 2: Move vortex while manipulating spin (adiabatic passage)
0 100 200 300 MW pulse length (ns)
1
0.96
Rel. P
L (
a.u
.)
0.92
0.98
0.94
Laser
CPW
MW
• Confirmed coherence by observing
Rabi oscillations about B1’
AHP to B1 Rabi about B1’
Laser
CPW B1
B1’
0 100 200 300 MW pulse length (ns)
1
0.96
Rel. P
L (
a.u
.)
0.92
0.98
0.94
• Vortex relaxes after voltage step in ≈100ns.
• MW pulse begins 100ns after CPW step.
• Minimal reduction in oscillation amplitude.
-2
0
2
4
30
0
Vortex position
MO
KE
0
By (mT)
