This document provides an overview of quantum computing, including: 1. There are two types of quantum computers - universal gate models that change gates over time to calculate circuits, and quantum annealers that set parameters first and obtain an answer. 2. Existing quantum computers are limited by noise and errors and cannot directly implement logical circuits, though variational algorithms like VQE are widely used. 3. Quantum hardware requires cryostats for cooling and controlling superconducting qubits, while software includes libraries for converting problems to the Ising model solved by annealers.

1. Quantum Computing Overview
1
2019.02.21 updated
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2. Quantum Computer
Using the quantum physics
Quantum annealer
Set the params first and get the final value for the answer
Universal gate model
Changing the gate timely to calculate the circuit
United states and China Japan and Canada
Calculation time
q[0]
q[1]
H
H H H
H
H
X
X H H
X
X
H
H
Annealing time
Gate
Qubit
Measurement
Qubit
Interaction Jij
h
Two types of Quantum Computer in Japan
There are two types of Quantum Computer, one is called universal model and another is quantum annealer.

3. 3
arXiv:1512.02206v4 [quant-ph] 22 Jan 2016
What is the Computational Value of Finite Range Tunneling?
On 2015 Nasa and Google announced they achieves x100,000,000 speed up for ising model.
When Quantum Computer becomes a trend

4. 0 1
1 0
0 1
0
11
1
00
Matter Wave
About Quantum
Cla
ssi
cal
Qu
ant
um
S
i
z
e
Large
Small
In a quantum world the matter has another
character of “wave” which can use as wave.

5. 5
About Hardware
Cryostat
equips
Controlling
cooling
Power
supply
and
measurem
ent
Frames
Chip inside
Cryostat
Usually superconducting qubits is used for hardware

6. X M
M
｜0〉
｜0〉
1.initialized to 0 2.combination of quantum gate 3.measurement
Universal Gate
3 steps of initialize, calculation and measurement.
X
H
X Y Z H
Pauli Hadamard
CNOT etc...
R
Phase shift
Quantum state among the calculation.

7. Input Error correction QPU
Usually existing quantum computer is so called NISQ(Noisy Intermediate-Scale Quantum)
Universal gate model and NISQ
The existing universal model cannnot digitize the circuit and the logical circuit directly go to backend.
Error correction
Output

8. Quantum gate model and VQE
Variational Quantum Eigensolver is now widely used for the calculations.
Quantum Classical
Quantum Calc1
Quantum Calc2
Quantum Calc3
New params
Optimization

9. Quantum Annealing
After making the QUBO, the ising model machine solve the problem inside the hardware.
Python libraries
QUBO equation
QUBO matrix
Ising matrix
Ising model machine
Applica
tion
Middle
ware
Hardwa
re
QUBO
conversion
Answer(Ising)
Answer(QUBO)
arXiv:1512.02206v4 [quant-ph] 22 Jan 2016
What is the Computational Value of Finite
Range Tunneling?
Global Minimum
Local minimum

10. 10
Contact Info
MDR Inc.
Location: Hongo2-40-14-3F, Bunkyo-ku, Tokyo, Japan
Business: Quantum Computing
Contact: info@mdrft.com
URL: https://mdrft.com