Single-Spin Tunneling Force Microscopy for characterization of paramagnetic defects in electronic materials
Abstract
The objective of this proposal is to develop and demonstrate a single-spin, electron spin resonance (ESR) microscopy technique capable of providing atomic scale spatial resolution. To achieve this goal, a previously developed scanning probe method (force detected single electron tunneling) has been combined with the concept of spin-dependent tunneling to enable spin states to be converted into charge states that can be detected by electrostatic force. A theoretical analysis has been performed which quantitatively shows that such single spin detection is possible using tunneling between a pair of E centers in silicon dioxide, one in a scanning probe tip and the other at the sample surface. This technique is expected to work over a broad range of temperatures, including room temperature, due to the strength that electrostatic forces provide compared to magnetic dipolar forces that have been used for single-spin detection in the past. The demonstration of this new spin microscopy technique requires a series of technical milestones to be achieved: (i) Using crystalline silicon at 5 degrees Kelvin, a nanometer sized metallic probe tip is employed to image and measure the electrical current flowing through a single pair of paramagnetic defects, a single phosphorus donor near the silicon surface and a dangling bond state at the silicon surface (now demonstrated); (ii) By manipulation of the paramagnetic states with magnetic resonance, a change of an applied electrical current through a single defect pair is measured, demonstrating single-spin electrically detected magnetic resonance; (iii) Using the ability to independently verify magnetic resonance conditions of individual defect pairs, the force detected magnetic resonance experiment will be then be conducted; (iv) Once this is established, these experiments are repeated with different paramagnetic systems and at higher temperatures, gradually approaching room temperature. For the project period between Fall 2015 and Fall 2016, it is aimed to accomplish (i) and (ii) with the goal to demonstrate single spin detection of a phosphorus donor atom at low temperature. Once this new single spin force microscopy concept is demonstrated, magnetic resonance spectra of individual, highly localized defects will become available, providing information about the defectÕs chemical identity with atomic scale spatial resolution. Additionally, control and readout of single electron spins provided by this technique may also be useful for future spin-based quantum information applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510547
Entities
People
- Clayton Williams
Organizations
- Army Contracting Command
- United States Army
- University of Utah