Synopsis: Quantum Computers Have a Fit

With the right algorithm, quantum computers could tackle ubiquitous problems such as least-squares fitting of large data sets.

As researchers were snaring the Higgs boson at CERN, the LHC machines were cranking out gigabytes of data each second. Even with the uninteresting bits filtered out, modern large-scale science creates mind-boggling amounts of data, causing standard techniques like curve fitting to run into a brick wall. Quantum computing—harnessing nonlocality and entanglement to make solving really hard problems more efficient—might have the prescription for this headache. In a paper in Physical Review Letters, Nathan Wiebe at the University of Waterloo, Canada, and colleagues propose an algorithm to improve the data analyzer’s best friend, least-squares fitting, on a quantum computer.

The authors built upon earlier theoretical work by Harrow et al. [see Phys. Rev. Lett. 103, 150502 (2009)] investigating a quantum method for finding expectation values of the solutions to systems of linear equations. Wiebe et al. adapt this algorithm to estimate the quality of a least-squares fit to an exponentially large data set (the kind that stymies classical computers) without having to obtain a full solution first and without having to fully characterize the state of the quantum computer (a process called quantum state tomography).

When realistic fault-tolerant quantum computing becomes available, the algorithm of Wiebe et al. could be used to find concise, continuous fitting functions for a given bounded approximation error. From a more general perspective, the result not only applies to one of the most widely used analysis techniques in science, but shows that quantum computing can find use outside of niche applications like prime-number factoring. – David Voss


Announcements

More Announcements »

Subject Areas

Quantum Information

Previous Synopsis

Next Synopsis

Materials Science

Doing a Crack Job on Aluminum

Read More »

Related Articles

Viewpoint: Photon Qubit is Made of Two Colors
Optics

Viewpoint: Photon Qubit is Made of Two Colors

Single particles of light can be prepared in a quantum superposition of two different colors, an achievement that could prove useful for quantum information processing. Read More »

Synopsis: Ten Photons in a Tangle
Quantum Information

Synopsis: Ten Photons in a Tangle

An entangled polarization state of ten photons sets a new record for multiphoton entanglement. Read More »

Synopsis: Quantum States Made with a Pluck
Quantum Information

Synopsis: Quantum States Made with a Pluck

A proposed method of generating phonon states for quantum applications uses a single electron trapped in a suspended carbon nanotube. Read More »

More Articles