They are billed as machines that will change the future, but quantum computers themselves are still in the future. All the same, scientists have been working on developing a working quantum computer for years now, and the frenzied competition to be the first has yielded a new record -- a 53-qubit quantum simulator.
Building a quantum computer has gone from a far-off dream of a few university scientists to an immediate goal for some of the world's biggest companies. Tech giants Intel, Microsoft, IBM, and Google are all plowing tens of millions of dollars into quantum computing, which aims to harness quantum mechanics to vastly accelerate computation. Yet the contenders are betting on different technological horses: No one yet knows what type of quantum logic bit, or qubit, will power a practical quantum computer. Google, often considered the field's leader, has signaled its choice: tiny, superconducting circuits. Its group has built a nine-qubit machine and hopes to scale up to 49 within a year--an important threshold. At about 50 qubits, many say a quantum computer could achieve "quantum supremacy" and do something beyond the ken of a classical computer, such as simulating molecular structures in chemistry and materials science, or solving problems in cryptography. Small startup company ionQ, a decided underdog, is sticking with its preferred technology: trapped ions.
Mechanical objects have important practical applications in the fields of quantum information and metrology as quantum memories or transducers for measuring and connecting different types of quantum systems. Here, we experimentally demonstrate a high-frequency bulk acoustic wave resonator that is strongly coupled to a superconducting qubit using piezoelectric transduction with a cooperativity of 260. Our device requires only simple fabrication methods and provides controllable access to a multitude of phonon modes. We demonstrate quantum control and measurement on gigahertz phonons at the single-quantum level.
From afar, it looks like a steampunk chandelier. It is, in fact, one of the most sophisticated quantum computers ever built. The processor inside has 50 quantum bits, or qubits, that process tasks in a (potentially) revolutionary way. Normally, information is created and stored as a series of ones and zeroes. Qubits can represent both values at the same time (known as superposition), which means a quantum computer can theoretically test the two simultaneously. Add more qubits and this hard-to-believe computational power increases.
Google is leading the pack when it comes to quantum computing. The company is testing a 20-qubit processor – its most powerful quantum chip yet – and is on target to have a working 49-qubit chip by the end of this year. Qubits, or quantum bits, can be a mixture of 0 and 1 at the same time, making them potentially more powerful than classical bits. And if everything goes to plan, the 49-qubit chip will make Google the first to build a quantum computer capable of solving certain problems that are beyond the abilities of ordinary computers. Google set itself this ambitious goal, known as quantum supremacy, in a paper published last July.