Featured Research

from universities, journals, and other organizations

When scaling the quantum slopes, veer for the straight path

Date:
October 24, 2013
Source:
Princeton University
Summary:
Researchers have found that the "landscape" of quantum control -- a representation of quantum mechanics that allows the dynamics of atoms and molecules to be manipulated -- can be unexpectedly simple, which could allow for ready control of quantum operating devices at the nanoscale.

Princeton University researchers found that the “landscape” for quantum control (above) — a representation of quantum mechanics that allows the dynamics of atoms and molecules to be manipulated — can be unexpectedly simple, which could help scientists realize the next generation of technology by harnessing atoms and molecules to create small but incredibly powerful devices. Scientists achieve quantum control by finding the ideal radiation field (top of the graphic) that leads to the desired response from the system. Like a mountain hiker, a scientist can take a difficult, twisting path that requires frequent stops to evaluate the next step (right path). Or, they can opt for a straighter trail that cuts directly to the summit (left path). The researchers provide in their paper an algorithm that scientists can use to identify the starting point of the straight path to their desired quantum field.
Credit: Image courtesy of Arun Nanduri

Like any task, there is an easy and a hard way to control atoms and molecules as quantum systems, which are driven by tailored radiation fields. More efficient methods for manipulating quantum systems could help scientists realize the next generation of technology by harnessing atoms and molecules to create small but incredibly powerful devices such as molecular electronics or quantum computers.

Of course, controlling quantum systems is as painstaking as it sounds, and requires scientists to discover the ideal radiation field that leads to the desired response from the system. Scientists know that reaching that state of quantum nirvana can be a long and expensive slog, but Princeton University researchers have found that the process might be more straightforward than previously thought.

The researchers report in the journal Physical Review A that quantum-control "landscapes" -- the path of a system's response from the initial field to the final desired field -- appears to be unexpectedly simple. Although still a mountain of a task, finding a good control radiation field turns out to be very much like climbing a mountain, and scientists need only choose the right path. Like a hiker, a scientist can take a difficult, twisting path that requires frequent stops to evaluate which step to take next. Or, as the Princeton researchers show, they can opt for a straighter trail that cuts directly to the summit.

The researchers observe in their paper that these fast tracks toward the desired control field actually exist, and are scattered all over the landscape. They provide an algorithm that scientists can use to identify the starting point of the straight path to their desired quantum field.

The existence of nearly straight paths to reach the best quantum control was surprising because the landscapes were assumed to be serpentine, explained first author Arun Nanduri, who received his bachelor's degree in physics from Princeton in 2013 and is working in the laboratory of Herschel Rabitz, Princeton's Charles Phelps Smyth '16 *17 Professor of Chemistry.

"We found that not only can you always climb to the top, but you can climb along a simple path to the top," Nanduri said. "If we could consistently identify where these paths are located, a scientist could efficiently climb the landscape. Looking around for the next good step along an unknown path takes great effort. However, starting along a straight path requires you to look around once, and you can keep walking forward with your eyes closed, as it were."

Following a straighter path could be a far more efficient way of achieving control of atoms and molecules for a host of applications, including manipulating chemical reactions and operating quantum computers, Nanduri said. The source of much scientific excitement, quantum computers would use "qubits" that can be entangled to potentially give them enormous storage and computational capacities far beyond the capabilities of today's digital computers.

If the Princeton research helps scientists quickly and easily find the control fields they need, it could also allow them to carry out improved measurements of quantum systems and design new ones, Nanduri said.

"We don't know if our discovery will directly lead to futuristic quantum devices, but this finding should spur renewed research," Nanduri said. "If straight paths to good quantum control solutions can be routinely found, it would be remarkable."


Story Source:

The above story is based on materials provided by Princeton University. The original article was written by Morgan Kelly. Note: Materials may be edited for content and length.


Journal Reference:

  1. Arun Nanduri, Ashley Donovan, Tak-San Ho, Herschel Rabitz. Exploring quantum control landscape structure. Physical Review A, 2013; 88 (3) DOI: 10.1103/PhysRevA.88.033425

Cite This Page:

Princeton University. "When scaling the quantum slopes, veer for the straight path." ScienceDaily. ScienceDaily, 24 October 2013. <www.sciencedaily.com/releases/2013/10/131024160519.htm>.
Princeton University. (2013, October 24). When scaling the quantum slopes, veer for the straight path. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2013/10/131024160519.htm
Princeton University. "When scaling the quantum slopes, veer for the straight path." ScienceDaily. www.sciencedaily.com/releases/2013/10/131024160519.htm (accessed July 30, 2014).

Share This




More Computers & Math News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

It's Not Just Facebook: OKCupid Experiments With Users Too

It's Not Just Facebook: OKCupid Experiments With Users Too

Newsy (July 29, 2014) If you've been looking for love online, there's a chance somebody has been looking at how you're looking. Video provided by Newsy
Powered by NewsLook.com
Why Facebook Wants You To Download Its Messenger App

Why Facebook Wants You To Download Its Messenger App

Newsy (July 29, 2014) Facebook will start requiring users to download a separate Messenger application if they wish to continue using Facebook for mobile messaging. Video provided by Newsy
Powered by NewsLook.com
Teen's Phone Ignites Under Her Pillow; How Real Is The Risk?

Teen's Phone Ignites Under Her Pillow; How Real Is The Risk?

Newsy (July 28, 2014) A Texas teen's Samsung phone apparently ignited while she slept, but what was the real problem here? Video provided by Newsy
Powered by NewsLook.com
Zillow Snaps Up Web Real Estate With Trulia Deal

Zillow Snaps Up Web Real Estate With Trulia Deal

Reuters - US Online Video (July 28, 2014) Zillow's decision to buy rival Trulia is just one step in a continuing string of acquisitions, and Zillow CEO Spencer Rascoff is already thinking about his next big deal. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins