AVS 49th International Symposium
    Magnetic Interfaces and Nanostructures Thursday Sessions
       Session MI+NS-ThA

Invited Paper MI+NS-ThA5
Magnetic Resonance Force Microscopy at Millikelvin Temperatures

Thursday, November 7, 2002, 3:20 pm, Room C-205

Session: Magnetic Imaging
Presenter: H.J. Mamin, IBM Almaden Research Center
Authors: H.J. Mamin, IBM Almaden Research Center
R. Budakian, IBM Almaden Research Center
D. Rugar, IBM Almaden Research Center
Correspondent: Click to Email
Magnetic resonance force microscopy (MRFM) offers the promise of combining the spectral resolving power and three-dimensional imaging capabilities of magnetic resonance with the high resolution of scanning probe techniques. The greatest payoffs are expected once it is possible to detect and manipulate individual spins. There is now evidence that one of the greatest obstacles to reaching this goal is that of thermally-driven fluctuations in the magnetic tip, which interfere with the quantum state of the spins. For this reason, we have begun an effort to perform MRFM at millikelvin temperatures in a dilution refrigerator. Some essential technical improvements have been incorporated, included detection of the cantilever displacement with ultralow optical powers, and ultra-efficient generation of microwave fields using a superconducting resonator. Using this newly developed apparatus, we have successfully demonstrated MRFM on an ensemble of electron spins at millikelvin temperatures. We are investigating various nonequilibirum effects, including spin relaxation times, which will have important implications for the feasibility of single spin detection.