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Quantum Conductance Project/Graphene-Based Quantum Metrology

Summary:

The goal of the Quantum Conductance Project is to develop graphene metrology for intrinsic electrical standards, specifically near-room-temperature quantum Hall resistance standards.  Graphene is a new material with truly extraordinary electronic properties that enables new approaches in many areas where conventional materials are running into obstacles. Although conceptually grapheme is an unrolled carbon nanotube (CNT), graphene transcends limitations of CNTs by offering the potential to fabricate complete systems entirely out of graphene, ranging from the macro to nanoscale. The opportunities for both exciting new science and important applications have led to an explosion of research on graphene at universities, domestic and foreign national labs, and industrial labs.

Description:

Progress in fundamental electrical standards and electronics is usually incremental and based on brute force engineering with sporadic episodes of ingenuity. Graphene represents one of these rare opportunities to dramatically improve measurement capabilities by utilizing a completely new scientific principle. However, application of the truly unique characteristics of graphene requires measuring the physical properties and developing new fabrication methods. Our efforts are currently focused on developing grapheme to advance NIST’s core mission – specifically, the development of intrinsic quantum electrical standards and metrology to enable the development of innovative future electronics.

Since the first quantum Hall resistance (QHR) standards were developed over 25 years ago, fabrication of improved GaAs-GaAlAs heterostructures has been a goal of leading National Metrology Institutes (NMIs) around the world; however, they are consistently in short supply because of the difficulty in producing even moderate quality QHR standards. Operating today’s QHR devices requires extensive cryogenic equipment and expertise; thus NMIs currently disseminate resistance through artifact standards. These have limited accuracy and are inherently unstable, resulting in time consuming and costly calibrations. New grapheme-based QHR standards with higher temperature operation have the promise to greatly improve the dissemination of quantum based resistance metrology to customers.

In microelectronics, it is well known that the continuation of Moore’s Law is already facing major challenges in power management and is being confronted by the discreteness of matter itself. The U.S. semiconductor industry spends billions of dollars to make incremental advances and desperately needs technology that transcends CMOS limitations. The major semiconductor industries have established consortia such as the Nanoelectronics Research Initiative (NRI) to direct various laboratories (academic, national, and corporate) to come up with visionary solutions to the foreshadowed limitations in silicon. Graphene promises to be one of these potential solutions, and we will exploit the new opportunities for discovery offered by graphene that specifically apply to electrical metrology.

Major Accomplishments:

  • Organized collaboration with other NIST Laboratories and leading U.S. research groups
  • Fabricated exfoliated graphene on Si/SiO2 substrate
  • First fabrication of graphene devices at NIST in the Center for Nanoscale Science and Technology (CNST)
  • Measured external collaborator’s graphene quantum resistance standard against national standards to 3 %
Graphene Hall bar developed at NIST by undergraduate students.
Graphene Hall bar developed at NIST by undergraduate students.

Start Date:

January 1, 2008

End Date:

ongoing

Lead Organizational Unit:

EEEL

Facilities/Tools Used:

CNST Nanofabrication Facility

Staff:

David Newell

Contact

David Newell
(301) 975-4228

100 Bureau Drive, MS 8170
Gaithersburg, MD  20899-8170