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The quantum computer has been a dream of computer scientists for a long time. Based on the quantum theory, quantum computers may bring a fundamental to current computing models. However, research on quantum computers has been mainly focused on theoretical and laboratory experimental verification of the quantum model, but a solid-state realization has remained an outstanding challenge.

A research team led by Leonardo DiCarlo from Yale University has recently brought a breakthrough to the quantum computing realization. They created the first solid-state quantum processor in the world – taking a far step turning the quantum theory into real machines.

The processor, although a little rudimentary at mean time, is able to perform quite a few simple quantum tasks such as searching. Before this, the quantum algorithms can only be implement in laboratory environments using techniques such as nuclear magnetic resonance, cold ion trapand optical systems. This is the first time quantum information processing runs on a solid-state device.

In quantum computing, information are carried by “qubits” (quantum bits). Each qubit can regularly occupy two different energy states, which can be interpolated as “1” and “0” or “on” and “off” states of regular bits employed by conventional computers. However, according to the laws of quantum mechanics, the quibits can be put in a “superposition” of multiple states at the same time, producing greater information storage and processing power.

The main problem in implementing solid-state qubits is that it is difficult to maintain the qubits long enough. The research now produce artificial qubits, each consists of a billion aluminum atoms, lasting a microsecond, which is long enough to run simple operations. The processor they created uses a two-qubit interaction in a superconducting electronic circuit. The interactions take place in a photon based “quantum bus” developed by the Yale group earlier.

The paper of the detailed implementation of the quantum processor has been accepted by Nature, and has been published in Nature’s advanced online publication.