Physicists from Australia have created «walkie-talkie» for quantum chips

© Photo : CQC2TФизики from Australia set work quantum radioPhysicists from Australia have created «walkie-talkie» for quantum chips© Photo : CQC2TПодпишись to daily updates RIA Science

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. Physicists from Australia have learned to control individual qubits in the «crowd» of these cells, quantum memory, without disturbing their neighbours. This will significantly accelerate the creation of complex quantum computers, says the article, published in the journal Science Advances.

«Our system works like a radio – we can «tune in» to a relationship with a particular qubit is similar to how we switch between stations on the radio. In fact, each of them has its own unique address, which is extremely useful for creating a full-fledged quantum computers,» says Sam Hill (Sam Hile) from the University of New South Wales in Sydney (Australia).

Gil and his colleagues at the University, working under the guidance of Andy Jurca (Andrew Dzurak), for several years to develop the components required to build a full quantum computer. So, in 2010 they created a quantum single-electron transistor, and in 2012 — full silicon qubit on the basis of an atom of phosphorus-31.

In 2013, they assembled a new version of the qubit, which allows almost 100% accuracy to read the data from it and remained stable for a very long time. In October 2015, Zorak and his team have taken the first step to the creation of the first silicon quantum computer, combining the two qubit in module that performs the logical OR operation. Last year they managed to protect the qubits from noise, making a big step towards the creation of a «working» quantum computer.

Remained one step – learn how to integrate such qubits using the same semiconductor technology that the cell of the quantum memory. It was extremely hard, because «normal» semiconductor qubits can interact with each other only a short distance away.

Solving this problem in the beginning of last year, scientists are faced with another problem – qubits was extremely difficult to place on a silicon substrate so that they can interact with each other, and thus their contents could be changed without interfering with the operation of adjacent memory cells.

Gil and his colleagues solved this problem by not using «atomic» and «molecular» phosphorus qubits. In fact, they are no different from single-atom transistors Zwraca except for the fact that their center is not one but a few atoms of phosphorus-31 and a set of special antennas that produce directed beams of microwaves.

Adding «extra» phosphorus atoms noticeably changed the way in which their electrons «communicate» with these antennas, but did not affect the interaction between them. In fact, each set of particles began to react to different frequencies that is produced by these emitters. This allows the individual to control their condition, without affecting other qubits.

Scientists checked the work of such individual «radios» for qubits fabricated chip, which contained two cells, quantum memory with a single and two atoms of phosphorus-31. As shown by experiments, as each of them could change even in the case when they were only 16 nanometers from each other

Such «walkie-talkie», as physicists say, have a virtually infinite number of individual channels. To expand their numbers or need to add new phosphorus atoms, or to change their position relative to each other. This allows you to create very complex quantum chips without worrying about possible overlapping signals and interference, the authors conclude the article.

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