Harvard scientists from Russia and the United States have created the world’s first quantum computer, consisting of 51 qubits. As reported in July 2017 by Harvard University professor and co-founder of the Russian quantum center, Mikhail Lukin, this 51 qubit quantum computer has been created by using a technique called “cold atom”.
During the presentation of the report at the Fourth International Conference on Quantum Technologies ICQT-2017, held under the auspices of the Russian Quantum Center in Moscow, Lukin stated, “ the new machine has allowed his group to become leader of the pack in the ongoing race to create a full-fledged, fully functional quantum computer capable of replacing traditional silicon chip-based systems” (https://sputniknews.com/science/201707141055558774-russian-us-lukin-quantum-computer/).
These computers operate on quantum bits or “qubits” which is a unit of quantum information analogous to the classical bit. A quantum computer with a given number of qubits, which can be in two positions simultaneously, differs from a classical computer composed of the same number of classical bits, which can be in one of two states, 1 or 0. The computing power of a quantum computer can grow exponentially, as the number of qubits that can be manipulated is increased. In theory, a quantum computer with 50 manipulatable qubits is more powerful than the Sunway TaihuLight, the world’s fastest Chinese supercomputer. Therefore, the more qubits a quantum computer uses, the more processing power it has.
However, there are two main approaches to the creation of quantum computing: classical and adiabatic. The proponents of the classical approach want to create a “universal quantum computer”, whose qubits are “subject to the rules governing the operation of conventional digital devices”. The proponents of the adiabatic approach support a principle of operation that is “closer to the analogue computers of the beginning of the 20th century than to the digital devices of the present” (https://sputniknews.com/science/201707141055558774-russian-us-lukin-quantum-computer/).
Teams of scientists from different countries have recently announced that they were very close to creating an adiabatic machine. John Martinis, who worked at the University of California at Santa Barbara and is currently employed at Google, has furthered his research to become leader in this field. Since 2014, his research group has been working on a hybrid version of a universal quantum computer combining the elements of both the analog and digital approach to calculations. Despite this, Lukin and his team have gone much further than Martinis’ group.
Lukin’s team used an exotic “cold atom” technology for their quantum computer. According to Sputnik News, “discovered by Russian and American scientists, the approach consists of keeping a set of atoms inside special laser “cells”, and cooling them at extremely low temperatures. These atoms can then be used as qubits, because their stability of operation is preserved under a wide set of circumstances. This approach has allowed physicists to create a 51 qubit computer – the most powerful quantum computer in the world” (https://sputniknews.com/science/201707141055558774-russian-us-lukin-quantum-computer/).
Moreover, this computer has already proved its efficiency in practice by solving several physics problems, which are very difficult to solve with the help of traditional supercomputers. Nevertheless, “Lukin and his team plan to continue the experiments with their quantum computer. Lukin does not rule out testing the computer with the Shor’s algorithm, which allows for the hacking of most of the existing encryption systems based on the RSA algorithm. According to Lukin, a paper on the first results of the work of the Russian-US quantum computer has been accepted for publication in a peer-reviewed scientific journal” as reported by Sputnik News (https://sputniknews.com/science/201707141055558774-russian-us-lukin-quantum-computer/).

A propos de Marta TATLIAN