Imaging viscous flow of the Dirac fluid in graphene
- Harvard Univ., Cambridge, MA (United States); Univ. of Maryland, College Park, MD (United States). Quantum Technology Center; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Univ. of Delaware, Newark, DE (United States)
- Harvard Univ., Cambridge, MA (United States)
- Harvard Univ., Cambridge, MA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)
- Harvard Univ., Cambridge, MA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Harvard Univ., Cambridge, MA (United States); Harvard Univ., Cambridge, MA (United States). John Harvard Distinguished Science Fellows Program
- Harvard Univ., Cambridge, MA (United States); Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
- National Inst. for Materials Science, Tsukuba (Japan)
- Univ. of California San Diego, La Jolla, CA (United States)
- Harvard Univ., Cambridge, MA (United States); Univ. of Maryland, College Park, MD (United States). Quantum Technology Center; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Harvard Univ., Cambridge, MA (United States). Center for Brain Science
The electron–hole plasma in charge-neutral graphene is predicted to realize a quantum critical system in which electrical transport features a universal hydrodynamic description, even at room temperature. This quantum critical ‘Dirac fluid’ is expected to have a shear viscosity close to a minimum bound, with an interparticle scattering rate saturating1 at the Planckian time, the shortest possible timescale for particles to relax. Although electrical transport measurements at finite carrier density are consistent with hydrodynamic electron flow in graphene a clear demonstration of viscous flow at the charge-neutrality point remains elusive. In this work, we directly image viscous Dirac fluid flow in graphene at room temperature by measuring the associated stray magnetic field. Nanoscale magnetic imaging is performed using quantum spin magnetometers realized with nitrogen vacancy centres in diamond. Scanning single-spin and wide-field magnetometry reveal a parabolic Poiseuille profile for electron flow in a high-mobility graphene channel near the charge-neutrality point, establishing the viscous transport of the Dirac fluid. This measurement is in contrast to the conventional uniform flow profile imaged in a metallic conductor and also in a low-mobility graphene channel. Furthermore, via combined imaging and transport measurements, we obtain viscosity and scattering rates, and observe that these quantities are comparable to the universal values expected at quantum criticality. This finding establishes a nearly ideal electron fluid in charge-neutral, high-mobility graphene at room temperature4. Our results will enable the study of hydrodynamic transport in quantum critical fluids relevant to strongly correlated electrons in high-temperature superconductors9. This work also highlights the capability of quantum spin magnetometers to probe correlated electronic phenomena at the nanoscale.
- Research Organization:
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Organization:
- Japan Society for the Promotion of Science (JSPS); National Science Foundation (NSF); Swiss National Science Foundation; US Army Research Office (ARO); US Office of Naval Research (ONR); USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0001819; SC0012704; SC0019300
- OSTI ID:
- 1657154
- Report Number(s):
- BNL--216325-2020-JAAM
- Journal Information:
- Nature (London), Journal Name: Nature (London) Journal Issue: 7817 Vol. 583; ISSN 0028-0836
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Observation of hydrodynamic plasmons and energy waves in graphene
Hydrodynamic electron transport near charge neutrality
Journal Article
·
Tue Feb 21 19:00:00 EST 2023
· Nature (London)
·
OSTI ID:2234173
Hydrodynamic electron transport near charge neutrality
Journal Article
·
Tue Aug 11 20:00:00 EDT 2020
· Physical Review. B
·
OSTI ID:1800513