Date:  Monday, November 2, 2015.

Time: 1:00pm.

Room: N110 in the Howey physics building.

Thesis Advisor: Dragomir Davidovic

Committee:

Professor Dragomir Davidovic (School of Physics, advisor)

Professor Zhigang Jiang (School of Physics)

Professor Martin Mourigal (School of Physics)

Professor Michael Pustilnik (School of Physics)

Professor David Anderson (School of Electrical and Computer Engineering)

Abstract:

Recent technological innovations such as giant magnetoresistance and spin-transfer torque, along with a desire for researching the emergence of magnetism from a fundamental level, has led to much interest in understanding nanometer scale ferromagnets. In this dissertation, I use sequential electron tunneling to study the differential conductance spectra and magnetic properties of single cobalt and nickel particles below 5 nm in diameter, and observe a wealth of material-dependent effects. The spin-orbit interaction is a key mechanism in the observation of a variety of effects, including giant electron spin g-factors and shifts in the anisotropy energy of the magnetic particle upon the addition of a single electron. I show how such effects can lead to an effective magnetization blockade, which allows for the voltage control of magnetic hysteresis. I model the quantum mechanical system characteristics using master equations, and propose a new type of spin-transfer torque device that relies on the magnetization blockade effect.