China builds ten qubit quantum computer, They will scale to 20 qubits by end of this year and could beat the performance of any regular computer next year with a 30 qubit system.
A chinese research team led by Pan Jianwei is exploring three technical routes to quantum computers:
1. systems based on single photons,
2. ultra-cold atoms and
3. superconducting circuits.
Experimental set-up for multiphoton boson-sampling. The set-up includes four key parts: the single-photon device, demultiplexers, ultra-low-loss photonic circuit and detectors. The single-photon device is a single InAs/GaAs quantum dot coupled to a 2-µm-diameter micropillar cavity
Pan Jianwei and his colleagues – Lu Chaoyang and Zhu Xiaobo, of the University of Science and Technology of China, and Wang Haohua, of Zhejiang University – set two international records in quantum control of the maximal numbers of entangled photonic quantum bits And entangled superconducting quantum bits.
Pan doubling that manipulation of multi-particle entanglement is the core of quantum computing technology and has been the focus of international competition in quantum computing research.
In the photonic system, his team has made the first 5, 6, 8 and 10 entangled photons in the world and is at the forefront of global developments.
Last year, Pan and Lu Chaoyang developed the world’s best single photon source based on semiconductor quantum dots. Now, they are using the high-performance single photon source and electronically programmable photonic circuit to build a multi-photon quantum computing prototype to run the Boson Sampling task.
The Chinese photonic computer is 10 to 100 times faster than the first electronic computer, ENIAC, and the first transistor computer, TRADIC, in running the classical algorithm.
The Hefei reporter ‘quantum device, called a boson sampling machine, can now carry out calculations for five photons, but at a speed 24,000 times than previous experiments.
ENIAC contained 17,468 vacuum tubes, 7200 crystal diodes, 1500 relays, 70,000 resistors, 10,000 capacitors and approximately 5,000,000 hand-soldered joints. It could perform 5000 simple addition or subtraction operations per second. ENIAC could perform 500 floating point operations per second.
The Chinese team led by Pan, Zhu Xiaobo and Wang Haohua have broken that record. They dependent developed a superconducting quantum circuit containing 10 superconducting quantum bits and successfully entangled the 10 quantum bits through a global quantum operation.
They will try to design and manipulate 20 superconducting quantum bits by the end of the year. They also plan to launch a quantum cloud computing platform by the end of this year.
“Our architecture is feasible to be scaled up to a larger number of photons and with a higher rate to race against increasingly advanced computers,” they said in the research paper.
Professor Scott Aaronson, who is based at the University of Texas at Austin and proposed the idea of the boson sampling machine, questioned whether it was useful to compare the latest results with technology developed over 60 years ago, but he said the research had shown ” Exciting experimental progress “.
“It’s a step towards boson sampling with say 30 photons or some number that’s large enough that no one will have to squint or argue about whether a quantum advantage has been attained,” he said.
Araronson said one of the main purposes of making boson sampling machines was to prove that quantum devices could be shown to have an advantage in one area of complex calculations over existing types of computer.
“Doing so would answer the quantum computing sceptics and help pave the way towards universal quantum computation,” he said.
Boson sampling is considered as a strong candidate to demonstrate ‘quantum computational supremacy’ over classical computers. However, previous proof-of-principle experiments suffered from small photon number and low sampling rates owing to the inefficiencies of the single-photon sources and multiport optical interferometers. Here, we develop two central components for high-performance boson sampling: robust multiphoton interferometers with 99% transmission rate and actively demultiplexed single-photon sources based on a quantum dot–micropillar with simultaneously high efficiency, purity and indistinguishability. We implement and validate three-, four- and five-photon boson sampling, and achieve sampling rates of 4.96 kHz, 151 Hz and 4 Hz, respectively, which are over 24,000 times faster than previous experiments. Our architecture can be scaled up for a larger number of photons and with higher sampling rates to compete with classical computers, and might provide experimental evidence against the extended Church–Turing thesis.