Potential for spin-based information processing in a thin-film molecular semiconductor.

Organic semiconductors are studied intensively for applications in electronics and optics, and even spin-based information technology, or spintronics. Fundamental quantities in spintronics are the population relaxation time (T1) and the phase memory time (T2): T1 measures the lifetime of a classical bit, in this case embodied by a spin oriented either parallel or antiparallel to an external magnetic field, and T2 measures the corresponding lifetime of a quantum bit, encoded in the phase of the quantum state. Here we establish that these times are surprisingly long for a common, low-cost and chemically modifiable organic semiconductor, the blue pigment copper phthalocyanine, in easily processed thin-film form of the type used for device fabrication.

Spin-based diagnostic of nanostructure in copper phthalocyanine-C60 solar cell blends.

Nanostructure and molecular orientation play a crucial role in determining the functionality of organic thin films. In practical devices, such as organic solar cells consisting of donor-acceptor mixtures, crystallinity is poor and these qualities cannot be readily determined by conventional diffraction techniques, while common microscopy only reveals surface morphology. Using a simple nondestructive technique, namely, continuous-wave electron paramagnetic resonance spectroscopy, which exploits the well-understood angular dependence of the g-factor and hyperfine tensors, we show that in the solar cell blend of C(60) and copper phthalocyanine (CuPc)-for which X-ray diffraction gives no information-the CuPc, and by implication the C(60), molecules form nanoclusters, with the planes of the CuPc molecules oriented perpendicular to the film surface.

The initialization and manipulation of quantum information stored in silicon by bismuth dopants.

A prerequisite for exploiting spins for quantum data storage and processing is long spin coherence times. Phosphorus dopants in silicon (Si:P) have been favoured as hosts for such spins because of measured electron spin coherence times (T2) longer than any other electron spin in the solid state: 14 ms at 7 K with isotopically purified silicon. Heavier impurities such as bismuth in silicon (Si:Bi) could be used in conjunction with Si:P for quantum information proposals that require two separately addressable spin species.

Ultralong copper phthalocyanine nanowires with new crystal structure and broad optical absorption.

The development of molecular nanostructures plays a major role in emerging organic electronic applications, as it leads to improved performance and is compatible with our increasing need for miniaturization. In particular, nanowires have been obtained from solution or vapor phase and have displayed high conductivity or large interfacial areas in solar cells. In all cases however, the crystal structure remains as in films or bulk, and the exploitation of wires requires extensive postgrowth manipulation as their orientations are random.

Prospective evaluation of endoluminal venous stents in the treatment of the May-Thurner syndrome.

The May-Thurner syndrome is an acquired stenosis of the left common iliac vein causing pain, edema, or deep venous thrombosis (DVT). The patency and behavior of endoluminal venous stents for this condition was evaluated in this study. Patients with the May-Thurner lesion treated with endoluminal stenting from 1997 to 2000 were evaluated according to an institutional review board-approved protocol.