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© 2017 IBM
IBM Systems for Cognitive Solutions – Ehningen – 12th of July 2017Albert Frisch, PhD - [email protected]
Quantum Computing
IBM Q
2 © 2017 IBM
1st wave of Quantum Revolution
lasers
flash memory
atomic clocks
GPS
sensors
3 © 2017 IBM
IBM Qpress anouncement on 6th of March 2017:
„The First Universal QuantumComputers for Business and Science”
press anouncement on 17th of May 2017:
16- and 17-qubit processors
IBM aims at constructing commercial IBM Q systems with ̴50 qubits in the next few years to demonstrate capabilities beyond today’s classical systems
quantum advantage
IBM 16-qubit processor
4 © 2017 IBM
motivation
Lev S. Bishop - https://developer.ibm.com/open/events/dw-open-tech-talk-qiskit-and-quantum-computing/
5 © 2017 IBM
computing revolution
6 © 2017 IBM
quantum simulator
“Hardware-efficient Quantum Optimizer for Small Molecules and Quantum Magnets”, A. Kandala et al., arxiv 1704.05018 (2017)
chemistrymagnetism
IBM 7-qubit processorused to „encode“electron orbitals
7 © 2017 IBM
quantum-enhanced machine learning
“Advances in quantum machine learning”, J. C. Adcock et al., arxiv 1512.02900 (2015)
e.g. deep learning neural network
Ising model at thermal equilibrium
→ minimize energy for optimal learningsource: wikipedia
data processing forquantum neural networks
solving systems of linear equationsclassical: 𝑂(𝑁), quantum: 𝑂(log(𝑁))
hidden layers
visible layervisible layer
inp
ut
ou
tpu
t
𝑤11(2)𝑤11
(1)𝑤11(3)
8 © 2017 IBM
The Quantum World
classical computer
is in a deterministic state at any time
defined by all bits of the computer
𝒏 bits → 𝟐𝒏 possible states, one at a time
quantum computer
superposition of states possible
„all states at the same time“
uses qubits to take advantage of quantum speedup
50 qubits → 1015 states simultaneously available
e.g. ۧ𝜓 = a ۧ000 + 𝑏 ۧ001 + 𝑐 ۧ010 + 𝑑| ۧ011 + ⋯
9 © 2017 IBM
a quantum algorithm
The spread
First part of the algorithm is to make an equal
superposition of all 2n states by applying H gates
The problem
The second part is to encode the problem into this states; put phases on all 2n states
The magic
The magic of quantum algorithms is to interfere all these states back to a few outcomes containing the
solution
10 © 2017 IBM
optimization
same as traditionalcomputer
restrictive
optimizationquantum chemistrymaterial sciencesquantum dynamics
highpartial
three steps of development
1. Quantum Annealer2. Analog Quantum Computer3. Universal Quantum Computer applications
computational powergenerality
optimizationquantum chemistrymaterial sciencesquantum dynamics
very highcomplete
cryptographysearching
machine learning
>100.000 qubits50 – 100 qubits
11 © 2017 IBM
Quantum Volume
12 © 2017 IBM
qubits
IBM Quantum Experience - quantumexperience.ng.bluemix.net/
superposition
z.B.
Bloch sphere
„Bit 0“
„Bit 1“
13 © 2017 IBM
measurement and quantum gates
either | ۧ0
or | ۧ1
probability
measurement
180°
rotationsz.B.
Hadamard creates superposition
50%
50%
measurement
→ no classical equivalent exists
controlled-NOTfor entanglement
e.g.
| ۧ𝜓 =1
2(| ۧ00 + | ۧ11 )
„quantum XOR“
14 © 2017 IBM
quantum algorithm
1. initialization of all qubits in ۧ|02. sequence of operations on single or multiple qubits3. measurement (read-out) concludes algorithm
multiple repetitions for statistical claims necessary
1. 2. 3.
15 © 2017 IBM
decoherence
IBM Quantum Experience – http://quantumexperience.ng.bluemix.net/
amplitude
T1energy relaxation
phase
T2dephasing
be
tte
r
longer coherence times mean lower error rateswhich allows more time to compute
loss of quantum information
16 © 2017 IBM
IBM quantum computer
“Demonstration of a quantum error detection code using a square lattice of four superconducting qubits”, A.D. Córcoles et al., Nat. Comm., 6:6979 (2015)
cryostattemperature
0.014 K
14 mK
100 mK
800 mK
4 K
radio-frequency
control and readout lines
coupling between
qubits via resonators
superconducting
qubits
17 © 2017 IBM
a scalable quantum chip architecture
“Building logical qubits in a superconducting quantum computing system”, J. Gambetta et al., npj Quantum Information 3, 2 (2017)
8 Qubits / 4 Buses / 8 Readouts
16 Qubits / 22 Buses / 16 Readouts
fault-tolerant quantum computing via the surface codetopological quantum computing
logical qubits formed by delocalized states of data qubits
error correction on data qubits
18 © 2017 IBM
IBM Quantum Experience
www.ibm.com/quantumexperience
Over 40,000 users
All 7 continents
>150 colleges andUniversities
Over 300,000 experiments
quantum computeras an IBM cloud service
19 © 2017 IBM
live demo 2-qubit Grover algorithm
20 © 2017 IBM
QISKit - OPENQASMe.g. quantum teleportation
https://developer.ibm.com/open/openprojects/qiskit/
quantum score fileOPEMQASM 2.0
21 © 2017 IBM
QISKit – Python API and SDK
https://developer.ibm.com/open/openprojects/qiskit/
execute OPENQASM code from Python, e.g. Jupyter Notebook
22 © 2017 IBM
© 2017 IBM23
backup
24 © 2017 IBM
DiVincenzo‘s criteria
set of criteria necessary for quantum computation:
A scalable physical system with well characterised qubits.1.
The ability to initialise the state of the qubits to a simple fiducial state.2.
Long relevant coherence times.3.
4. A “universal” set of quantum gates.
A qubit5. -specific measurement capability.
additional criteria for quantum communication:
The ability to interconvert stationary and flying qubits.6.
The ability to transmit flying qubits between specified locations.7.
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QK
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25 © 2017 IBM
transmon qubit
[1] “Charge insensitive qubit design derived from the Cooper pair box”, J. Koch et al., Phys. Rev. A 76, 042319 (2007)[2] “Coupling Superconducting Qubits via a Cavity Bus”, J. Majer et al., Nature 449, 443-447 (2007)[3] “Demonstration of a quantum error detection code using a square lattice of four superconducting qubits”, A.D. Córcoles et al., Nat. Comm., 6:6979 (2015)
a „transmission-line shunted plasma oscillation qubit“ [1]
coupling qubits via cavity bus [2]
Josephson junction
26 © 2017 IBM
microwave control and read-out
“Hardware-efficient Quantum Optimizer for Small Molecules and Quantum Magnets”, A. Kandala et al., arxiv 1704.05018 (2017)
27 © 2017 IBM
Grover search algorithm
„A fast quantum mechanical algorithm for database search“, L. Grover, arXiv:quant-ph 9605043 (1996)
• finds element always in time 𝑂 𝑁
with probability 1 − 𝑂1
𝑁classical algorithm 𝑂 𝑁
• optimal search algorithm
• amplitude amplification
1.
2.
3.
28 © 2017 IBM
qubit architecture
https://developer.ibm.com/open/events/dw-open-tech-talk-qiskit-and-quantum-computing/
2Qubits/1Bus/2Readouts
4Qubits/4Bus/4Readouts 8Qubits/4Bus/8Readouts
29 © 2017 IBM
transmon - Josephson junction
30 © 2017 IBM
live demo 2-qubit Grover algorithm
31 © 2017 IBM
Live Demo
32 © 2017 IBM
QISKit - running quantum algorithms
