Study of Energy Transport and Dissipation with Atomic Resolution in 1D- and 2D-Materials
Abstract
Title: Study of Energy Transport and Dissipation with Atomic Resolution in 1D- and 2D-MaterialsEnergy transport and dissipation play a critical role in the operation and performance characteristics of all nanoelectronic devices. Further, novel transport properties with no counterparts in the bulk are expected to arise in nanoscale systems. For example, heat transfer in nanomaterials, such as graphene nanoribbons (GNRs), is expected to feature a divergent thermalconductivity due to its quasi 1-D characteristics. Moreover, novel energy dissipation and scattering characteristics are expected to arise in nanoscale systems. Thus, controlling dissipation and heat flow in these systems is widely predicted to pose both significant opportunities and challenges for realizing quantum transport properties in 2D materials and topologically protectedsystems. Another illustrative example of a nanoscale dissipative phenomena is the process of migration of atoms in electronic devices due to momentum transfer between charge carriers and defects in the lattice, which plays a key role in determining the function of nanoscale electronic and memrisitive devices. Several other examples where atomic scale dissipation is poorlyunderstood include friction (both mechanical friction and quantum friction) and near-field, photon-based energy transfer. Key to making rapid progress in understanding energy transport and dissipation in these systems is the development of experimental tools to directly record temperature fields with a spatial resolution of single digit nanometers while measuring energyflow and generation with a resolution of a few eV/second (attowatt), i.e. the energy associated with making or breaking a few chemical bonds.In this project, we will develop custom-fabricated scanning probes that feature high-resolution superconducting quantum interference device (SQUID)-based temperature sensors to accomplish attowatt-resolution scanning calorimetry. Our strategy to accomplish this groundbreaking technological advance is to fabricate, characterize and integrate these probes into a low temperature (< 2 Kelvin) scanning tunneling microscope and establish three key capabilities andmeasurement techniques: 1) Quantitative measurements of temperature fields at low temperatures with nm spatial resolution and K temperature resolution, 2) heat flow calorimeters capable of attowatt measurements and 3) scanning heat flow calorimeters (agai used for probing thermal transport in 1D systems. These innovative measurement capabilities will be employed to tackle the following key questions:1) Does the thermal conductivity of GNRs diverge with length, as suggested by the Fermi-Ulam-Pasta theory, due to non-ergodic behavior of quasi 1-D systems such as graphene nanoribbons?2) Do quantum thermal oscillations exist in graphene-based structures as have been predicted by recent theoretical studies? If so, can such quantum oscillations be experimentally observed using atomic-resolution probes that we will develop in this project?3) How does the scattering of carriers with defects in 2D materials result in dissipation and loss of coherence? In topological materials, how do carriers in topological edge and surface states interact with defects on the surfaces and within the bulk of a material?4) In memristive devices, such as those based on monolayer MoS2, is resistive switching caused by local heating and thermal ion diffusion, or are charge carriers and potentials more intimately coupled to ion migration?Successfully answering these key questions is critical for making progress towards carbon-based nanoelectroni and nanometrology.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 08, 2020
- Source ID
- N000142012476
Entities
People
- Pramod Sangi Reddy
Organizations
- Board of Regents of the University of Michigan
- Office of Naval Research
- United States Navy