* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download m NV Centers in Quantum Information Technology ! De-Coherence Protection &
Bell test experiments wikipedia , lookup
Electron configuration wikipedia , lookup
Quantum electrodynamics wikipedia , lookup
Theoretical and experimental justification for the Schrödinger equation wikipedia , lookup
Many-worlds interpretation wikipedia , lookup
Ferromagnetism wikipedia , lookup
Ising model wikipedia , lookup
Canonical quantization wikipedia , lookup
Interpretations of quantum mechanics wikipedia , lookup
Quantum group wikipedia , lookup
History of quantum field theory wikipedia , lookup
Orchestrated objective reduction wikipedia , lookup
Quantum key distribution wikipedia , lookup
Quantum machine learning wikipedia , lookup
Hydrogen atom wikipedia , lookup
Hidden variable theory wikipedia , lookup
Franck–Condon principle wikipedia , lookup
Nitrogen-vacancy center wikipedia , lookup
Quantum computing wikipedia , lookup
Quantum decoherence wikipedia , lookup
Quantum state wikipedia , lookup
EPR paradox wikipedia , lookup
Quantum entanglement wikipedia , lookup
Bell's theorem wikipedia , lookup
Relativistic quantum mechanics wikipedia , lookup
Symmetry in quantum mechanics wikipedia , lookup
Algorithmic cooling wikipedia , lookup
m NV Centers in Quantum Information Technology ! De-Coherence Protection & Teleportation! Brennan MacDonald-de Neeve, Florian Ott, and Leo Spiegel! The NV Center! • Point Defect in Diamond! • Interesting Physics in negatively charged state NV-1! NC • Total electron spin S=1! • 14N Nuclear Spin I=1! VC Di Vincenzo Criteria! 1. Well-defined qubits! 2. Initialization! 3. tcoherence > tgate operation! 4. Universal set of quantum gates! 5. Qubit specific read-out! 6. Convert from stationary to mobile qubit! 7. Faithful transmission! Relevant Ground State Energy Structure! B0 = 500 G! |1⟩e! 2.9 MHz! 1.4 GHz! 5.1 MHz! |0⟩e! |é⟩N! |ê⟩N! Relevant Ground State Energy Structure! B0 = 500 G! |1⟩e! Electron Spin Modulation:! MW Rabi Driving at 1.4 GHz with driving strength 40 MHz! 2.9 MHz! 1.4 GHz! 5.1 MHz! |0⟩e! |é⟩N! |ê⟩N! Relevant Ground State Energy Structure! B0 = 500 G! |1⟩e! Electron Spin Modulation:! MW Rabi Driving at 1.4 GHz with Rabi frequency at 40 MHz! 2.9 MHz! • 2 qubit register! • qubit modulation via Rabi driving! • entanglement through hyperfine interaction! 1.4 GHz! 5.1 MHz! |0⟩e! |é⟩N! Electron Spin Modulation:! RF Rabi Driving at 2.9 MHz with Rabi frequency at 30 kHz! |ê⟩N! Spin Initialization from Excited State! 1) Electron Spin using LASER pumping! 532 nm! S=0! mS=0! mS=+/–1! N. B. Manson et al. Phys. Rev. B 47, 104303 (2006). ! Spin Initialization from Excited State! 1) Electron Spin using LASER pumping! 2) Nuclear Spin using LASER pumping at B = 500 G! 532 nm! S=0! mS=0! mS=+/–1! N. B. Manson et al. Phys. Rev. B 47, 104303 (2006). ! V. Jacques et al. Phys. Rev. Lett. 102, 057403 (2011). ! FIG. 2 (color online). Nuclear-spin polarization mechanism. deterministic quantum tele- the other spin state (Fig. 1d). This optical pumping mechanism allows re attractive candidates for high-fidelity spin state initialization24,27: from the data in Fig. 1d, we 1 single-shot detecing, their estimate a preparation error into the mS 5 0 ground state of Hanson 3–6 d qubits . Here we demon- 0.3 6 0.1%, which is a drastic reduction of the 11 6 3% preparation nt of a multi-spin quantum b te system by implementing a 150 ts states with mS 5 0. A typical es originally developed in 10 s we study, is shown in Fig. 1c y read-out of the electronic N Vvacancy B). Under resonant excitation PL Spectrum of opticallyV excited 1 centre in diamond, A1 decays with time owing to a NV Center:! o three nearby nuclear spin NVA A NV A NV 0.1 ates that we induces shelving into Ex versely, can distinguish ! al pumping mechanism allows le shot by mapping it onto, • m = 0 is bright 5,8 data : from 1d, we (Ex)! S in Fig. MW onic spinthe . Finally, we show 10 μm he mS 5 of (A )! mS = ±1 • 0 mground = -1state is dark demonstrate initialization, mS = 0 S 1 nread-out of the 11 6 3% preparation in a single experic d chniques suitable for exten115 b 1,000 pave the way for a test of 100 NV A Ex NV A and the implementation of 80 A1 110 800 Ex 60 ion protocols. 40 600 vacancy centre (NV) in dia-A 1 20 A system for investigating Atate 15 0 Ex 400 ent spin coherence9–12 with a 0 1 2 3 4 5 10 e, the host nitrogen nuclear 200 A1 5 MW isotopic I 5 1) and nearby ±1 mS =the 0 0 erfine interactions with mS = 0 0 10 20 30 40 50 0 2 4 6 8 10 12 14 g development of few-spin Time (μs) Laser detuning (GHz) ested as building blocks for ,000 mputation18100 and distributed Figure 1 | Resonant excitation and electronic spin preparation of a Ex NV A nitrogen–vacancy centre. a, Scanning electron microscope image of a solid A1 ications require 80 high-fidelity 800 immersion lens representative of those used in the experiments (for details, see 60 spins. There ment of multiple Supplementary Information). The overlaid sketch shows the substitutional 40 few-spin sysnt control over 600 nitrogen and the adjacent vacancy that form the NV. Inset, scanning confocal 20 stsL.for the simultaneous pre- 477, Robledo et al. Nature 574–578 (2011).! microscope image of NV A (logarithmic colour scale). kct, 1,000 counts. 0 f400 multi-spin registers, 0 1 2 3which 4 5 b, Energy levels used to prepare and read out the NV’s electronic spin (S 5 1 in Read-Out! Intensity (kct s–1) Intensity (kct s–1) Intensity Fraction of outco deterministic quantum tele- the other spin state (Fig. 1d). This optical pumping mechanism allows re attractive candidates for high-fidelity spin state initialization24,27: (ii) p Fig. = 1 1d, we from the data in 0.2 1 ing, their single-shot detec- estimate a preparation error into the mS 5 0 ground state of Hanson d qubits3–6. Here we demon- 0.3 6 0.1%, which is a drastic reduction of the 11 6 3% preparation nt of a multi-spin quantum 0.6 a b mI = {0, +1} te system by implementing 150 ts states with mS 5 0. A typical es originally developed in preparation 0.4 10 s we study, is shown in Fig. 1c y read-out of the electronic N Vvacancy B). Under resonant excitation p=1 PL Spectrum of opticallyV excited 1 centre in diamond, (iii) A1 with Center:! time owing to a 0.2 NV o decays three nearby nuclear spin NVA A NV A NV 0.1 ates that we induces shelving into Ex versely, can distinguish 2.874 2.876 2.878 2.880 2.882 ! al pumping mechanism allows le shot by mapping it onto, Microwave frequency (GHz) • 5,8. data mS in = Fig. 0weisshow bright : from 1d, we (Ex)! MW onic spinthe Finally, 10 μm he mS 5 state of (A )! mS = ±1 • 0 mground = -1 is dark demonstrate initialization, mS = 0 S 1 c Ø Can also be used to read out nread-out of the 11 6 3% preparation in a single experic d mI by using a CNOT gate:!NV B chniques suitable for exten115 b 1,000 mI = –1 pave the way for a test of NV A 0.8 Ex 100 NV A and the implementation of 80 A1 110 800 Ex N 60 ion protocols. 40 0.6 600 vacancy centre (NV) in dia-A 1 20 A system for investigating Atate 15 0 Ex 400 ent spin coherence9–12 with a 0 |0〉 1 2 3 4 5 10 0.4 e, the host nitrogen nuclear 200 A1 5 MW isotopic I 5 1) and nearby ±1 mS =the 0.20 0 erfine interactions with mS = 0 0 10 20 30 40 50 0 2 4 6 8 10 12 14 p=2 g development of few-spin Time (μs) Laser detuning (GHz) ested as building blocks for 0.0 ,000 mputation18100 and distributed Figure 1 | Resonant excitation and electronic spin 0 preparation 5 of a 10 15 Ex NV A nitrogen–vacancy centre. a, Scanning electron microscope image of a solid A1 ications require high-fidelity 80 800 Counts in N see = 3 repetitions immersion lens representative of those used in the experiments (for details, 60 spins. There ment of multiple Supplementary Information). The overlaid sketch shows the substitutional 40 few-spin sysnt control over 600 nitrogen the adjacent vacancy that form the NV. scanning confocal 20 Figure 3 and Nuclear spin preparation andInset, read-out. a, Measurement-based stsL.for the simultaneous preRobledo et al. Nature 477, 574–578 (2011).! microscope image of NV A (logarithmic colour scale). kct, 1,000 counts. 0 400 14 f multi-spin registers, 0 1 2 3which 4 5 Read-Out! Intensity (kct s–1) Fraction of occurrences Intensity (kct s–1) Intensity | spin. Earth’s ambient magnetic field of preparation of used a single b, Energy levels to prepareN andnuclear read out the NV’s In electronic spin (S 5 1 in Decoherence! Decoherence is caused by all the undesired interactions of a quantum state with its environment which shortens its lifetime.! D h spins! 1 free evolution ) P 0 τ 0 100 (π/2)x (π/2)x 114 B (G) G. de Lange et al. Science 330, 60–63 (2010).! 0 0.2 0.4 τ (µs) 0.6 0.8 uantum control pulses and NV centers appear as y level diagrams of the NV center electron spin agnetic field splits the NV spin triplet electronic d by the spin sublevels mS = 0 (labeled j0〉) and NV1. For the pulsed experiments, the same Rabi probed using Ramsey interference. Solid line is Decoherence! Decoherence is caused by all the undesired interactions of a quantum state with its environment which shortens its lifetime.! D h spins! 1 free evolution ) P 0 τ 0 100 (π/2)x (π/2)x 114 B (G) G. de Lange et al. Science 330, 60–63 (2010).! 0 0.2 0.4 τ (µs) 0.6 0.8 uantum control pulses and NV centers appear as Ø Dynamic decoupling: flipping of the qubit spin state to y level diagrams of the NV center electronPeriodic spin agnetic fieldaverage splits the NV spinthe triplet electronic out interactions with the environment.! d by the spin sublevels mS = 0 (labeled j0〉) and Viola et al.experiments, Phys. Rev Athe 58,same 2733Rabi (1998). ! NV1. ForL.the pulsed probed using Ramsey interference. Solid line is ownloaded from http://rsta.royalsocietypublishing.org/ on May 20, 2015 Dynamical Decoupling! 4751 Review. Robust dynamical decoupling (a) (b) y Sx Sz (c) –x Sz Sy t t y y t/2 (d) Sz y Cn–1 t y x Cn–1 Hahn Echo! N t/2 x Cn–1 Cn–1 Carr–Purcell–Meiboom–Gill! yN XY-4! mical decoupling pulse sequences. The empty and solid rectangles represent 90◦ and A. and M. Souza et al. Phil. R. of Soc. 370, 4748–4769 (2012). ! pectively, N represents theTrans. number iterations of the cycle. (a) Initial state Hahn spin-echo sequence. (c) CPMG sequence. (d) CDD sequence of order N , d C = t. and decoupling. We experimentally demonstrate g a two-qubit register in diamond operating at room uantum tomography reveals that the qubits involved ation are protected as accurately as idle qubits. We rover’s quantum search algorithm1, and achieve ticularly promising for the tures12–22, in which differen spins, superconducting res form different functions. D to be decoupled at its own Decoherence in multi-qubit gates! 1) couple to a Qubits Unprotected each other but also quantum gate to environment! e– n b c Protected storage: Decoupling e– n Protected quantum gate e– d NV cen C C N V C n C e |1↑〉 Environment Environment |1 Environment Nuclear drivin Gate Decoupling Gate + decoupling z N. van der Sar et al. Nature 484, 82–86 (2012). ! x y R X( ) 14 and tion decoupling. and decoupling. We experimentally We experimentally demonstrate demonstrate ticularly ticularly promising promising for thef 12–22 gusing a two-qubit a two-qubit register register in diamond in diamond operating operating at room at room , in which , in which differen d tures12–22 tures uantum re. Quantum tomography tomography reveals reveals that the that qubits the qubits involved involved spins,spins, superconducting superconducti res ation operation are protected are protected as accurately as accurately as idleasqubits. idle qubits. We We form different form different functions. functiD 1 , and1, achieve and achieve to be decoupled to be decoupled at its own at its rm rover’s Grover’s quantum quantum searchsearch algorithm algorithm Decoherence in multi-qubit gates! 2)b Qubits decoupled d c c Protected Protected Protected Protected from each other and quantum storage: storage: quantum gate gate Decoupling Decoupling environment! 1) to b a Qubits a couple Unprotected Unprotected each otherquantum but alsogate quantum gate to environment! e– e– n n e– e– n n e– e– n dNV cenN C C N C n e V C e |1↑〉 Environment Environment Environment Environment C |1|1 Environment Environment Nuclear Nuclea drivin Gate Gate decoupling + decoupling Decoupling Decoupling Gate +Gate z N. van der Sar et al. Nature 484, 82–86 (2012). ! x y z y x R X( ) 14 1 operation and tion decoupling. and decoupling. and decoupling. We experimentally We experimentally We experimentally demonstrate demonstrate demonstrate ticularly ticularly promising ticularly promising for promi thef 12–22 12–22 12–22 ggates using a two-qubit using a two-qubit a register two-qubit register in diamond register in diamond inoperating diamond operating at operating room at room at room , intures which , in which differen , in wh d tures tures uantum erature. re. Quantum tomography Quantum tomography tomography reveals reveals thatreveals the that qubits the that qubits involved the qubits involved involved spins,spins, superconducting spins, superconducti supercon res ation operation gate are operation protected are protected are as protected accurately as accurately as accurately as idleasqubits. idleasqubits. idle Wequbits. We formWe different form form different functions. different functiD f 1 , and1, achieve and1, achieve and to achieve be decoupled to be decoupled to be at decoupled its own at its perform rm rover’s Grover’s quantum Grover’s quantum search quantum search algorithm search algorithm algorithm Decoherence in multi-qubit gates! 1) to b Protected 2)b Qubits only d dNV cen dN a Qubits a couple a Unprotected b decoupled c c c3) Qubits Protected Protected Unprotected Unprotected Protected Protected Protected each otherquantum but also from each other and quantum decoupled storage: storage: storage: quantum gate quantum gate gate quantum gate quantum gate from gate C C C Decoupling Decoupling Decoupling to environment! environment! environment! N e– e– e–n n e– n e– e–n n e– n e– e–n n C n e V C e e |1↑〉 |1|1 Environment Environment Environment Environment Environment Environment Environment Environment Environment Nuclear Nuclea drivinN Gate Gate Gate Gate +Gate decoupling +Gate decoupling + decoupling Decoupling Decoupling Decoupling z N. van der Sar et al. Nature 484, 82–86 (2012). ! x y z y x RX( x) 14 1 Qubit Coupling Qubit Coupling Generally desirable Fast coupling for fast qubit manipulation Qubit Coupling Generally desirable Fast coupling for fast qubit manipulation But we pay a price We also get faster coupling to the environment ”Fast” and ”Slow” Qubits Encode Physical Qubits in: ”Fast” and ”Slow” Qubits Encode Physical Qubits in: I atomic states ”Fast” and ”Slow” Qubits Encode Physical Qubits in: I atomic states I superconducting circuits ”Fast” and ”Slow” Qubits Encode Physical Qubits in: I atomic states I superconducting circuits I quantum dots ”Fast” and ”Slow” Qubits Encode Physical Qubits in: I atomic states I superconducting circuits I quantum dots I NV centers Two Qubit Gates Two Qubit Gates Difficult Scenario Using ”fast” qubit as the control bit Two Qubit Gates Difficult Scenario Using ”fast” qubit as the control bit Question Can we use dynamical decoupling to make a gate using the ”fast” qubit as our control bit? ”Fast” and ”Slow” Qubits; NV Centers ”Fast” qubit: electronic spin ”Fast” and ”Slow” Qubits; NV Centers ”Fast” qubit: electronic spin I GHz energy splitting ”Fast” and ”Slow” Qubits; NV Centers ”Fast” qubit: electronic spin I GHz energy splitting I T2 = 3.5µs ; Rabi 2π pulse: 20ns ”Fast” and ”Slow” Qubits; NV Centers ”Fast” qubit: electronic spin I GHz energy splitting I T2 = 3.5µs ; Rabi 2π pulse: 20ns ”Slow” qubit: nuclear spin ”Fast” and ”Slow” Qubits; NV Centers ”Fast” qubit: electronic spin I GHz energy splitting I T2 = 3.5µs ; Rabi 2π pulse: 20ns ”Slow” qubit: nuclear spin I MHz energy splitting ”Fast” and ”Slow” Qubits; NV Centers ”Fast” qubit: electronic spin I GHz energy splitting I T2 = 3.5µs ; Rabi 2π pulse: 20ns ”Slow” qubit: nuclear spin I MHz energy splitting I T2 = 5.3ms ; Rabi 2π pulse: 30µs Two Qubit Gates Imagine Two Qubit Gates Imagine Two Qubit Gates Imagine Two Qubit Gates Imagine Two Qubit Gates Imagine Two Qubit Gates Not obvious whether this can work Two Qubit Gates Not obvious whether this can work Building a 2-Qubit Gate Electronic Spin Nuclear Spin mS = 0 : |0i mS = −1 : |1i mI = +1 : |↑i mI = 0 : |↓i Building a 2-Qubit Gate Electronic Spin Nuclear Spin mS = 0 : |0i mS = −1 : |1i mI = +1 : |↑i mI = 0 : |↓i Building a 2-Qubit Gate Electronic Spin Nuclear Spin mS = 0 : |0i mS = −1 : |1i mI = +1 : |↑i mI = 0 : |↓i Timescales ( µs ) Building a 2-Qubit Gate Electronic Spin Nuclear Spin mS = 0 : |0i mS = −1 : |1i mI = +1 : |↑i mI = 0 : |↓i Timescales ( µs ) Building a 2-Qubit Gate Electronic Spin Nuclear Spin mS = 0 : |0i mS = −1 : |1i mI = +1 : |↑i mI = 0 : |↓i Timescales ( µs ) Building a 2-Qubit Gate Decoupling Pulse Sequence τ − X − 2τ − Y − τ Building a 2-Qubit Gate Decoupling Pulse Sequence τ − X − 2τ − Y − τ Electronic Qubit in State |0i exp( −iσ~z θ0 )exp( −iσ~x 2θ1 )exp( −iσ~z θ0 ) Building a 2-Qubit Gate Decoupling Pulse Sequence τ − X − 2τ − Y − τ Electronic Qubit in State |0i exp( −iσ~z θ0 )exp( −iσ~x 2θ1 )exp( −iσ~z θ0 ) Electronic Qubit in State |1i exp( −iσ~x θ1 )exp( −iσ~z 2θ0 )exp( −iσ~x θ1 ) Building a 2-Qubit Gate Special case 1 τ = (2n + 1)π/A Building a 2-Qubit Gate Special case 1 τ = (2n + 1)π/A Example Building a 2-Qubit Gate Special case 1 τ = (2n + 1)π/A Example Building a 2-Qubit Gate Special case 1 τ = (2n + 1)π/A Example Building a 2-Qubit Gate Special case 2 τ = 2nπ/A Building a 2-Qubit Gate Special case 2 τ = 2nπ/A Example Building a 2-Qubit Gate Special case 2 τ = 2nπ/A Example Building a 2-Qubit Gate Special case 2 τ = 2nπ/A Example Building a 2-Qubit Gate Combine special cases 1 and 2 obtain a conditional rotation gate Experimental Results Experimental Results CNOT Gate ( θ = π ) Process fidelity: Fp = Tr (χideal χ) = 83% Experimental Results CNOT Gate ( θ = π ) Process fidelity: Fp = Tr (χideal χ) = 83% For a State |ψi = α |0i + β |1i ρ = |ψi hψ| Experimental Results CNOT Gate ( θ = π ) Process fidelity: Fp = Tr (χideal χ) = 83% For a State |ψi = α |0i + β |1i ρ = |ψi hψ| For an Operator A = αI + βσx +P γσy + δσz ε(ρ) = AρA† = i,j χij Ei ρEj † Testing Gate Robustness Inject noise into the diamond Reduce T2,SE from 251µs to 50µs Testing Gate Robustness Inject noise into the diamond Reduce T2,SE from 251µs to 50µs Reduce RF drive power to nuclear spin Gate time increases to 120µs Testing Gate Robustness Single qubit decoupling apply (τ − π − τ )N Inject noise into the diamond Reduce T2,SE from 251µs to 50µs Reduce RF drive power to nuclear spin Gate time increases to 120µs Testing Gate Robustness Single qubit decoupling apply (τ − π − τ )N Inject noise into the diamond Reduce T2,SE from 251µs to 50µs Reduce RF drive power to nuclear spin Gate time increases to 120µs T2,N=16 = 234µs Testing Gate Robustness Apply CNOT Input state (|0i + i |1i) ⊗ |↑i Desired output state √ |ψi = (|0 ↑i + |1 ↓i)/ 2 Testing Gate Robustness Apply CNOT Input state (|0i + i |1i) ⊗ |↑i Desired output state √ |ψi = (|0 ↑i + |1 ↓i)/ 2 Testing Gate Robustness Apply CNOT Input state (|0i + i |1i) ⊗ |↑i Desired output state √ |ψi = (|0 ↑i + |1 ↓i)/ 2 State Fidelity N = 16 : F = reaches 96% p hψ| ρ |ψi Running Grover’s Algorithm Recall: Search Algorithm I Find entry in list of N elements I Number of oracle calls scales as √ N Running Grover’s Algorithm Recall: Search Algorithm I Find entry in list of N elements I Number of oracle calls scales as √ N Running Grover’s Algorithm Running Grover’s Algorithm Final State Fidelity > 90% Summary Summary I Can construct 2-qubit gate protected from decoherence Summary I Can construct 2-qubit gate protected from decoherence I Especially useful when control bit is ”fast” Summary I Can construct 2-qubit gate protected from decoherence I Especially useful when control bit is ”fast” I Achieved process fidelities above 80%, and state fidelities above 90% using an NV center Summary I Can construct 2-qubit gate protected from decoherence I Especially useful when control bit is ”fast” I Achieved process fidelities above 80%, and state fidelities above 90% using an NV center I Ultimate goal: < 10−4 Quantum Teleportation NV - Centers Framework • Unconditional teleportation • • Any state can be transmitted Remoteness • Sender and reciever are reasonably separated (3m) Entanglement • Remote entanglement between NV electrons • Local entanglement: Spin rotation / Spin-selective excitation Electron-Photon • Local entanglement: Quantum interference photon detection Photon-Photon Teleporter Setup Configuration • Alice NV-Center: Transmission Qubit (1) Nuclear spin Messenger Qubit (2) Electron spin • Bob NV-Center: Reciever Qubit (3) Electron spin • Qubits 2 & 3 entangled in | i23 Teleporter Setup Initialization • • Transmission Qubit initialized in |1i1 • Projective measurement of Messenger • Prior to entanglement Source State | i1 = ↵|0i1 + |1i1 • After entanglement to avoid Dephasing Teleporter Setup Final State Final State in Bell basis: • | i1 ⌦ | i23 1 = [| 2 +| +| +| + + i12 (↵|1i3 |0i3 ) i12 (↵|1i3 + |0i3 ) i12 ( ↵|0i3 + |1i3 ) i12 ( ↵|0i3 |1i3 )] Teleportation • Interaction between Qubits 1 and 2 • CNOT followed by ⇡/2 Y-rotation of Transmitter • Projective measurements • Conditional Pauli-rotations Teleportation Interaction • Nuclear rotations controlled by Electron excitation level: Controlled ⇡/2 Y-rotation (on 1 controlled by 2) ⇡ Y-rotation (unconditional on 2) Controlled ⇡/2 Y-rotation (on 1 controlled by 2) • Effectively: ⇡/2 Y-rotation (unconditional on 1) Teleportation Interaction Overall state after interaction: • Ry1 (⇡ /2 )UCN OT (| i1 ⌦ | 1 [|11i12 (↵|1i3 |0i3 ) 2 + |01i12 (↵|1i3 + |0i3 ) + |10i12 (↵|0i3 |1i3 ) + |00i12 (↵|0i3 + |1i3 )] i23 ) = Teleportation Interaction Overall state after interaction: • Ry1 (⇡ /2 )UCN OT (| i1 ⌦ | 1 [|11i12 ( xz | i3 ) 2 + |01i12 ( x | i3 ) + |10i12 ( z | i3 ) + |00i12 ( | i3 )] i23 ) = Teleportation Measurement • Direct measurement on messenger • Projective measurement on transmitter • CNOT on |0i2 electron (on reinitialized messenger, controlled by transmitter) Direct measurement on messenger Teleportation Pauli rotations Depending on measurement: • |00i12 |10i12 |01i12 |11i12 7! 7 ! 7 ! 7 ! z x xz Results Tomography for Y on Bob’s side to confirm alignment of reference frames • 6 unbiased states transmitted. Fidelity 0.77 • Outlook Remote Entanglement Mutliple Qubits per node: • • NV Centers are a good candidate for Quantum networks Entanglement fidelity high enough to close detection loophole of Bell Inequality •