The Mass Spectrum of the 2-dimensional Conformal String

We present the mass spectrum of the tensionless string in 2 dimensions where it has been found that the space time conformal symmetry survives quantization. A BRST treatment of the physical states reveals that the string collapses into a massless particle, a result which agrees with the classical treatment.Comment: 18 pages, latex, no figure

Silicon Oxide Passivation of Single-Crystalline CVD Diamond Evaluated by the Time-of-Flight Technique

The excellent material properties of diamond make it highly desirable for many extreme electronic applications that are out of reach of conventional electronic materials. For commercial diamond devices to become a reality, it is necessary to have an effective surface passivation since the passivation determines the ability of the device to withstand high surface electric fields. In this paper we present data from lateral Time-of-Flight studies on SiO2-passivated intrinsic single-crystalline CVD diamond. The SiO2 films were deposited using three different techniques. The influence of the passivation on hole transport was studied, which resulted in the increase of hole mobilities. The results from the three different passivations are compared

Classical Interactions for Tensionless Strings

Using an ``action at a distance'' formulation we probe the possible classical interactions for tensionless strings, (the $T\to 0$ limit of the ordinary bosonic string.) We find $G_{\mu\nu}$ and $B_{\mu\nu}$ type interactions but no dilaton interactions.Comment: 9 pages, Late

Classical and Quantized Tensionless Strings

{}From the ordinary tensile string we derive a geometric action for the tensionless ($T=0$) string and discuss its symmetries and field equations. The Weyl symmetry of the usual string is shown to be replaced by a global space-time conformal symmetry in the $T\to 0$ limit. We present the explicit expressions for the generators of this group in the light-cone gauge. Using these, we quantize the theory in an operator form and require the conformal symmetry to remain a symmetry of the quantum theory. Modulo details concerning zero-modes that are discussed in the paper, this leads to the stringent restriction that the physical states should be singlets under space-time diffeomorphisms, hinting at a topological theory. We present the details of the calculation that leads to this conclusion.Comment: 34 pages, Latex, USITP 93-1

Determinants of customer satisfaction with socially responsible investments: Do ethical and environmental factors impact customer satisfaction with SRI profiled mutual funds?

Although much research has been published on green/ethical consumer behaviour, the question of how consumers evaluate pro-socially positioned products in the post-purchase stage is still virtually unexplored. This is troubling given the significance of post-purchase evaluations within general marketing theory. To address this gap in the literature, this study examines how a set of technical and functional quality attributes contribute to customer satisfaction in a socially responsible investment (SRI) setting. The results of the study show that perceived financial quality of the SRI mutual fund is the most important predictor of customer satisfaction. However, perceived social, ethical, and environmental (SEE) quality is also positively related to satisfaction for the SRI mutual fund. Based on these results, it is argued that although SEE quality is important to customers, marketers of pro-socially profiled products should primarily focus on conventional quality attributes, as a good SEE record unlikely to generate customer satisfaction alone.Customer satisfaction; ethics; perceived quality; socially responsible investment; mutual funds

A Picture of D-branes at Strong Coupling II. Spinning Partons

We study the Born-Infeld D-brane action in the limit when the string coupling goes to infinity. The resulting actions is presented in an arbitrary background and shown to describe a foliation of the world-volume by strings. Using a recently developed ``degenerate'' supergravity the parton picture is shown to be applicable also to supersymmetric D-branes.Comment: 14 pages, Late

Fe/V and Fe/Co (001) superlattices: growth, anisotropy, magnetisation and magnetoresistance

Some physical properties of bcc Fe/V and Fe/Co (001) superlattices are reviewed. The dependence of the magnetic anisotropy on the in-plane strain introduced by the lattice mismatch between Fe and V is measured and compared to a theoretical derivation. The dependence of the magnetic anisotropy (and saturation magnetisation) on the layer thickness ratio Fe/Co is measured and a value for the anisotropy of bcc Co is derived from extrapolation. The interlayer exchange coupling of Fe/V superlattices is studied as a function of the layer thickness V (constant Fe thickness) and layer thickness of Fe (constant V thickness). A region of antiferromagnetic coupling and GMR is found for V thicknesses 12-14 monolayers. However, surprisingly, a 'cutoff' of the antiferromagnetic coupling and GMR is found when the iron layer thickness exceeds about 10 monolayers.Comment: Proceedings of the International Symposium on Advanced Magnetic Materials (ISAMM'02), October 2-4, 2002, Halong Bay, Vietnam. REVTeX style; 4 pages, 5 figure

Hamiltonian BRST Quantization of the Conformal String

We present a new formulation of the tensionless string ($T= 0$) where the space-time conformal symmetry is manifest. Using a Hamiltonian BRST scheme we quantize this {\em Conformal String} and find that it has critical dimension $D=2$. This is in keeping with our classical result that the model describes massless particles in this dimension. It is also consistent with our previous results which indicate that quantized conformally symmetric tensionless strings describe a topological phase away {}from $D=2$. We reach our result by demanding nilpotency of the BRST charge and consistency with the Jacobi identities. The derivation is presented in two different ways: in operator language and using mode expansions. Careful attention is payed to regularization, a crucial ingredient in our calculations.Comment: 33pp (LaTeX), USITP-94-0

Null Branes in Curved Backgrounds

We consider null bosonic p-branes in curved space-times. Some exact solutions of the classical equations of motion and of the constraints for the null membrane in general stationary, axially symmetrical, four dimensional, gravity background are found.Comment: 19 pages, LaTeX, no figures. Extended version. To appear in Phys. Rev.

A Picture of D-branes at Strong Coupling

We use a phase space description to (re)derive a first order form of the Born-Infeld action for D-branes. This derivation also makes it possible to consider the limit where the tension of the D-brane goes to zero. We find that in this limit, which can be considered to be the strong coupling limit of the fundamental string theory, the world-volume of the D-brane generically splits into a collection of tensile strings.Comment: 14 pages, LaTe