Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Using graphene to create quantum bits

18.05.2017

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based quantum capacitor, compatible with cryogenic conditions of superconducting circuits, and based on two-dimensional (2D) materials.


This is an insulating boron nitride sandwiched between two graphene sheets.

Credit: ©EPFL/ LPQM

When connected to a circuit, this capacitor has the potential to produce stable qubits and also offers other advantages, such as being relatively easier to fabricate than many other known nonlinear cryogenic devices, and being much less sensitive to electromagnetic interference. This research was published in 2D Materials and Applications.

Normal digital computers operate on the basis of a binary code composed of bits with a value of either 0 or 1. In quantum computers, the bits are replaced by qubits, which can be in two states simultaneously, with arbitrary superposition. This significantly boosts their calculation and storage capacity for certain classes of applications. But making qubits is no mean feat: quantum phenomena require highly controlled conditions, including very low temperatures.

To produce stable qubits, one promising approach is to use superconducting circuits, most of which operate on the basis of the Josephson effect. Unfortunately, they are difficult to make and sensitive to perturbing stray magnetic fields. This means the ultimate circuit must be extremely well shielded both thermally and electromagnetically, which precludes compact integration.

At EPFL's LPQM, this idea of a capacitor that's easy to make, less bulky and less prone to interference has been explored. It consists of insulating boron nitride sandwiched between two graphene sheets. Thanks to this sandwich structure and graphene's unusual properties, the incoming charge is not proportional to the voltage that is generated. This nonlinearity is a necessary step in the process of generating quantum bits.

This device could significantly improve the way quantum information is processed but there are also other potential applications too. It could be used to create very nonlinear high-frequency circuits -- all the way up to the terahertz regime -- or for mixers, amplifiers, and ultra strong coupling between photons.

###

Laboratory of Photonics and Quantum Measurements LPQM (STI/SB)

Source: Nonlinear Graphene Quantum Capacitors for Electro-optics

sina.khorasani | EurekAlert!

More articles from Physics and Astronomy:

nachricht New 'styrofoam' planet provides tools in search for habitable planets
16.05.2017 | Lehigh University

nachricht International team solves mystery of colloidal chains
15.05.2017 | Northwestern University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

Im Focus: Laser pulses reveal the superconductors of the future

Thanks to innovative laser techniques, a class of materials shows a new potential for energy efficiency. The research is published in Nature Physics

Another step forward towards superconductivity at room temperature: an experiment at the cutting edge of condensed matter physics and materials science has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

Aerogels - the world's lightest solids: International project meeting of NanoHybrids at TUHH

15.05.2017 | Event News

 
Latest News

World's thinnest hologram paves path to new 3-D world

18.05.2017 | Information Technology

Using graphene to create quantum bits

18.05.2017 | Physics and Astronomy

Advancing cancer immunotherapy with computer simulations and data analysis

18.05.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>