Synopsis: A hybrid quantum computer

Separate groups have come up with designs on how to transfer quantum information between distinct computer architectures.
Synopsis figure
Credit: P. Bonderson and R. M. Lutchyn, Phys. Rev. Lett. (2011)

Like Mac and PC, quantum computers come in two forms, depending on how localized the information is. Researchers are looking into hybrid models that could combine the best of both systems. Two papers in Physical Review Letters describe possible interfaces for relaying information between the two quantum platforms.

Quantum computers store information in “qubits,” which are quantum combinations of ones and zeros. Traditionally, qubits have been recorded in some intrinsic property of an isolated system, like the spin of a trapped electron. The trouble is that any slight interaction with the environment will force the qubit to collapse into a specific state and lose information.

One possible solution to this problem is to use topological quantum computers, which store information in intertwined particle states, called anyons. If one imagines these anyons as checkers on a board, a computation would consist of swapping the pieces in a precise sequence. The quantum information is not localized on individual checkers, but is instead encoded in the way the anyon trajectories weave around each other in spacetime.

Topological qubits have yet to be fully realized, but they show promise as robust quantum storage units. By contrast, conventional qubits appear better suited for a variety of logic gates. To take advantage of both types of “quantum hardware,” Liang Jiang, from Caltech, and his colleagues have proposed a way to link topological qubits on the surface of a topological insulator to conventional qubits made from superconducting wire loops. Parsa Bonderson and Roman Lutchyn at Microsoft Station Q, Santa Barbara, have devised a similar sort of quantum bus to connect anyon-carrying nanowires with conventional quantum dots. – Michael Schirber

Correction (1 April 2011): The affiliation for Parsa Bonderson and Roman Lutchyn was corrected.


Announcements

More Announcements »

Subject Areas

Quantum Information

Previous Synopsis

Particles and Fields

A melting pot of protons

Read More »

Next Synopsis

Atomic and Molecular Physics

Free falling

Read More »

Related Articles

Viewpoint: Hiding a Quantum Cache in Diamonds
Quantum Information

Viewpoint: Hiding a Quantum Cache in Diamonds

Entanglement purification, a vital enabler for practical quantum networks, has been shown to be feasible with secluded nuclear memories in diamond. Read More »

Viewpoint: Classical Simulation of Quantum Systems?
Optics

Viewpoint: Classical Simulation of Quantum Systems?

Richard Feynman suggested that it takes a quantum computer to simulate large quantum systems, but a new study shows that a classical computer can work when the system has loss and noise. Read More »

Focus: <i>Landmarks</i>—Correcting Quantum Computer Errors
Quantum Physics

Focus: Landmarks—Correcting Quantum Computer Errors

In the mid-1990s, researchers proposed methods to preserve the integrity of quantum bits—techniques that may become the key to practical quantum computing on a large scale. Read More »

More Articles