ABSTRACT
Devices ............................................................................................. 101 4.3 Spin Injection and Transport in Organics: Spin Valve Experiments ............ 105
4.3.1 Organic Thin Films .......................................................................... 105 4.3.1.1 Sexithienyl (T6) Thin Films ................................................ 105 4.3.1.2 Tris 8-Hydroxyquinoline Aluminum (Alq3) Thin Films ......107 4.3.1.3 Other Organics ................................................................... 113
4.3.2 Organic Nanowires ........................................................................... 114 4.4 Spin Injection and Transport in Organics: Meservey-Tedrow Spin
Polarized Tunneling, Two-Photon Photoemission (TPPE), and μSR Experiments .................................................................................................. 118 4.4.1 Meservey-Tedrow Spin Polarized Tunneling ................................... 118 4.4.2 TPPE Spectroscopy .......................................................................... 119
4.4.2.1 Background ........................................................................ 119
Processing and storing of binary data are central to information technology. These functions are often implemented by manipulating the charge degree of freedom of carriers (electrons and holes) in solid state systems. For example, realization of the classical binary logic bits (“0” and “1”) requires two physically distinguishable states. In computer memories, such states are realized by different amounts of charge stored on a capacitor* or by two distinct voltage levels at some circuit node.† Processing of such charge based logic bits is performed by circuits consisting of switching devices such as metal oxide semiconductor field effect transistors (MOSFETs). An emerging technology dubbed “spintronics”‡ [1, 2], on the other hand, aims to harness the spin degree of freedom of carriers in lieu of charge to realize these core information processing and storage functionalities [3-6]. This technology has already revolutionized the storage density of hard drives [7, 8] and can potentially realize universal memory [9] and low-power computation [3, 10].
