Raymond Laflamme [email protected] www.iqc.ca From Quantum Science to Quantum Technologies Message -Quantum Information Science has taught us the right language in order to be able to talk and be talked to by quantum systems (atoms, molecules etc..) -From that knowledge we are learning of taking advantage of the quantum world and although quantum computers are still some time in the future, the impact of quantum sensors has already started to happen. The Quantum World “a place where there are no penalties for interference” Miriam Diamond, USEQIP student Undergraduate Summer Experimental Quantum Information Program https://uwaterloo.ca/institute-for-quantum-computing/programs/useqip Cycle of Discoveries Curiosity Social Impact Understanding Technology Control Successes of Quantum Information Science Discovery of the power of quantum • mechanics for information processing -new language for quantum mechanics Discovery of how to control quantum systems • Proof-of-concepts experiments • Successes of Quantum Information Science Discovery of the power of quantum • mechanics for information processing -new language for quantum mechanics Plus !! Discovery of how to control quantum systems • DevelopmentProof-of-concepts of practical experiments quantum information technologies • On thefirstfloor… Mike and Opehlia Lazaridis Quatnum Nano Center University of Waterloo Quantum Technologies today Made possible because the world in quantum Lasers LEDs MRI Transistors Quantum Information: The QUBIT Spin-based QIP Trapped Ions Superconducting Qubits Quantum Optics Trapped Atoms Quantum Dots Quantum Sensors Harnessing the quantum world will allows us to achieve: •! Greatest precision •! Greatest sensitivity •! Greatest selectivity •! Greatest robustness •! Greatest efficiency Quantum Information provides the right language and tools 13 Cl Cl C1 N S NMR quantum computing =|010> 13 C H 2 Cl Trichloroethylene Brief history of NMR Bloch and Purcell Applications of NMR -MRI -molecular structure -chemical analysis -concrete research -tire compositions - molecular dynamics -… Cl H1 S C5 C4 H Cl 3 NMR quantum computing C3 H2 C6 C7 C2 O H 5 H4 C1 O O Brief history of QIP achievements H •! laboratory feedback on quantum control •! theoretical challenges: DQC1 John Waugh 1 (I + αZ) 2 n I⊗ 2n •! development of experimental QECorrection •! … -push the quality of quantum control Challenge with inhomogeneity B+!B B B-!B "# "B+!B > "B > "B-!B 0 Z A rf inhomogeniety selective pulse " Y X ! Find a pulse sequence that keep the spins that are within a given homogenity bound and spread the other around the sphere 1 1 z 0.8 0.6 0.4 0.2 # of spins -1 1 2 3 y i rf inhomogeneity x i 64 1.0 Rx(90) R x(180)) 0.8 ! ! 0.6 64 0.4 (Ri (180)R i (180)) Ry(90) 0.2 amount of signal ! 1.5% 3.0% 4.5% 6.0% 7.5% rf inhomogeneity NMR Oil well logging Application to oil well logging by measuring presence of • water/oil ! Small pore Large pore •! porosity of rocks • motion of the liquid Amplitude ! Amplitude MRIL® Magnetic Resonance ImagingTime, Logging msec Time, msec Direct Measurements Produce Better Results The proof is in the logs. Halliburton's Magnetic Resonance Imaging Logging (MRIL®) is revolutionizing the openhole logging business through direct measurement of reservoir fluids, such as oil, gas, and water. Now, operators can identify water-free production zones and previously hidden pay zones in their wells using MRIL technology. Increasing reserves by providing a complete, accurate analysis of a low resistivity/low contrast interval Identifying commercial zones in a laminated, fine-grained sand and shale formation Improving completion success in a low permeability reservoir Establishing water-free oil production in a low resistivity zone … http://www.halliburton.com N S Measuring a magnetic field 0 Z 1 t+τ /2 " Y φ(t, τ )= µB(t)dt X t τ /2 − ! Ψ(φ(t, τ )) = 0 + eiφ(t,τ ) 1 1 | | z z z precession (t-� /2,t) y y y P rob( 0 0 )=Cos[φ(t, τ )] x x x | | 1 z z z Cos[F] �spin-echo �spin-echo precession 0.5 y y (t,t+� /2) y 5 10 15 20 25 30 x x x -0.5 -1 F Technology comparison MRFM (2004) MRFM (2007) SQUIDS (2008) MRFM (2009) Atom chip (2005) 10-8 10-6 10-4 10-2 100 Distance [m] 10nm 1!m Superconducting qubits as sensors History of superconducting (qu)bits •! long experience (> 50 year) of behavior at classical level. •! versatile and easily tunable •! (hopefully) relatively easily scalable •! one of the first quantum use: test quantum mechanics Superconducting qubits as sensors Superconducting qubit: mesoscopic system that using superconducting material to build ``artificial atoms’’ C=capacitance L=inductance Q=charge on the capacitance $=flux through the loop Potential Energy 2 x /2 2 E=hN LdQ 1 1 1 E = + Q2 = Φ2 + Q2 E=hN 2 dt 2C 2L 2C E=hN X or & 1 1 E = p2 + (q Λ)2 2 2 − Λ is the control parameter charge qubit Λ = Vg gate voltage phase qubit Λ = I ← bias current flux qubit Λ = Φ ← external flux ext ← Superconducting qubits as sensors Superconducting qubits: mesoscopic system that using superconducting material to build artificial atoms” Need to make energy level different: do this by adding a Josephson junction 100 Josephson junction 1 1 80 E = Φ2 + Q2 2L 2C 60 a) 40 20 + Ej cos(2πΦ/Φ0) -10 -5 5 10 b) Superconducting Qubits: A Short Review M. H. Devorety, A. Wallray, and J. M. Martinis Superconducting Circuits for Quantum Information: An Outlook M. H. Devoret and R. J. Schoelkopf, Science 339, 1169 (2013); Sensitivity vs resolution for our detector Lupascu’s quantum sensor Nature Communications, 3, 1324 (2012), preprint arXiv: 1301.0778. DARPA compilation (QUASAR) sensitivity of 3.3 pT Hz1/2 for a frequency of 10 MHz. Can we do better? NV centers Scientific American, Energy diagram October 2007 N V ! ! ! Explain how they work and the achievement of Yacoby NV centers a Excitation laser |1〉 2γ B Scanning diamond |–1〉 Yacoby, Nature Physics 9, 215, 2013 platform ωMW |0〉 MW coil Sensor NV z x y Target spins 50 nanometer above target Measure single spin Electron spins: “long coherence time” -> electronic resolution: 2.7 Å -room temperature -can initialized the qubit Nuclear spins: -measure electron spin resonance -> nuclear resolution: 6 Å Quantum sensors Neutron interferometry Dima Pushin D. A. Pushin,M. G. Huber, M. Arif,and D. G. Cory PRL 107, 150401 Collaboration of IQC, NIST and Brockhouse Institute Interesting use of neutron interferometers: non-destructive measurement at the atomic scale: characterize magnetic, nuclear, and structural properties of materials, protein structure, can be use on biological or cold material, fundamental studies in physics, information science and solid-state physics Quantum sensors Neutron interferometry -but the interferometer is fragile -neutron characteristics velocity about 1000m/s wavelength is about ~0.2 nm i.e. a few angstrom Dominant noise mode Quantum Error Correction Probability of success per gate: P ~(1 %) Probability of success for n gates Pn~(1 e)n: i.e.exponential decrease Classical error correction thought to require: •! discrete errors (bit flips.. does not work for analog devices) •! copying information (but no cloning theorem) •! measure the bits (destroy coherence) A simple family of code: Decoherence free subspaces: They are subspaces that are not affected by noise e.g. this this state state is not is invariant invariant wrt rotations + | ↑↓ − | ↓↑ | ↑↓ | ↓↑ Neutron interferometry an example of macroscopic quantum coherence 2 2 4 IO = "O = t r [1+ cos(#)] Measure the neutron Intensity. In this case that is the number of neutrons per unit time. = " 2 = 2 4 + 4 # 2 2 $ IH H r [(t r ) r t cos( )] Neutron interferometry an example of macroscopic quantum coherence Measure the neutron Intensity. |0> In this case that is the number of neutrons per unit time. |1> 1 1 1 3 4 1 2 4 3 2 2 2 |00> 1 1 |0> |01> 1 3 4 1 |10> 2 4 3 2 |1> |11>2 2 |0> |01> 1 3 4 1 |10> 2 4 3 2 |1> Neutron interferometry The 4/5 blade interferometer a robust again rotation No vibration 3 blade 8 Hz vibration 650 600 550 per 300 sec a b (220) ons 500 + beam blocks Neutr phase flag 450 O-beam -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 H-b eam neutron Phase flag rotation, (°) beam blocks detectors b 700 No vibration 4 blade 650 8 Hz vibration 600 550 on beam per 300 sec 500 neutr ons 450 perfect Si single crystal interferometer Neutr 400 c 350 neutron interferometer enclosure -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 beam motor Phase flag rotation, (°) low frequency vibration isolation table off-center mass off-center vibration vibration isolation pads isolation pads S/N ratio increased by 600 GEO600: gravitational wave detector Use Michaelson interferometer to precisely measure distance GEO600: gravitatinal wave detector Use Michaelson interferometer to precisely measure distance vacuum The Vacuum in Quantum Mechanics Potential Energy x2 /2 E=hN Ground state E=hN E=hN X or & P X Uncertainty relations Squeezed Ground state ∆X ∆P /2 × ≥ P X H. Grote,* K. Danzmann, K. L. Dooley, R. Schnabel, J. Slutsky, and H. Vahlbruch Max-Planck-Institut fu¨r Gravitationsphysik (Albert Einstein Institut) und Leibniz Universita¨ t Hannover, Callinstraße 38, 30167 Hannover, Germany GEO600: gravitational wave detector MFn vacuum system = 2 sequential photo diode = mode-cleaners mirror = (8m round-trip) 600m north arm (folded in vertical plane) generic electronics = electronic oscillator = Injection locked high-power MCn 600m east arm electronic mixer = laser system MPR (folded in vertical plane) T=0.09% 1064nm MCe BS MFe MSR OMC Michelson output signal + T=10% Data output Phase locked loop 14.9MHz