Quantum Logic Processor: A Mach Zehnder Interferometer based Approach

Quantum Logic Processors can be implemented with Mach Zehnder Interferometer(MZI) configurations for the Quantum logic operations and gates. In this paper, its implementation for both optical and electronic system has been presented. The correspondence between Jones matrices for photon polarizations and Pauli spin matrices for electrons gives a representation of all the unitary matrices for the quantum gate operations. A novel quantum computation system based on a Electronic Mach Zehnder Interferometer(MZI) has also been proposed. It uses the electron spin as the primary qubit. Rashba effect is used to create Unitary transforms on spin qubits. A mesoscopic Stern Gerlach apparatus can be used for both spin injection and detection. An intertwined nanowire design is used for the MZI. The system can implement all single and double qubit gates. It can easily be coupled to form an array. Thus the Quantum Logic Processor (QLP) can be built using the system as its prototype.Comment: 19 pages, 6 figures, 8 Table

Energy dependent wavelength of the ion induced nanoscale ripple

Wavelength variation of ion beam induced nanoscale ripple structure has received much attention recently due to its possible application in nanotechnology. We present here results of Ar$^+$ bombarded Si in the energy range 50 to 140 keV to demonstrate that with beam scanning the ripple wavelength increases with ion energy and decreases with energy for irradiation without ion beam scanning. An expression for the energy dependence of ripple wavelength is proposed taking into simultaneous effect of thermally activated surface diffusion and ion induced effective surface diffusion.Comment: REVTeX (4 pages), 3 EPS figure

Search for optical bursts from the gamma ray burst source GBS 0526-66

Attempts were made to detect optical bursts from the gamma-ray burst source GBS 0526-66 during Dec. 31, 1984 to Jan. 2, 1985 and Feb. 23 to Feb. 24, 1985, using the one meter reflector of the Kavalur Observatory. Jan. 1, 1985 coincided with the zero phase of the predicted 164 day period of burst activity from the source (Rothschild and Lingenfelter, 1984). A new optical burst photon counting system with adjustable trigger threshold was used in parallel with a high speed photometer for the observations. The best time resolution was 1 ms and maximum count rate capability was 255,000 counts s(-1). Details of the instrumentation and observational results are presented

Pion and Kaon dissociation in hot quark medium

Pion and kaon dissociation in a medium of hot quark matter is studied in the Nambu Jona-Lasinio model. The decay width of pion and kaon are found to be large but finite at temperatures much higher than the so called critical temperature of chiral or deconfinement transition, kaon decay width being larger. Consequently, pions and even kaons (with a lower density compared to pions) should coexist with quarks and gluons at such high temperatures. The implication of the above result in the study of Quark-Gluon plasma is discussed.Comment: Latex file with one postscript fil

The holographic fluid dual to vacuum Einstein gravity

We present an algorithm for systematically reconstructing a solution of the (d+2)-dimensional vacuum Einstein equations from a (d+1)-dimensional fluid, extending the non-relativistic hydrodynamic expansion of Bredberg et al in arXiv:1101.2451 to arbitrary order. The fluid satisfies equations of motion which are the incompressible Navier-Stokes equations, corrected by specific higher derivative terms. The uniqueness and regularity of this solution is established to all orders and explicit results are given for the bulk metric and the stress tensor of the dual fluid through fifth order in the hydrodynamic expansion. We establish the validity of a relativistic hydrodynamic description for the dual fluid, which has the unusual property of having a vanishing equilibrium energy density. The gravitational results are used to identify transport coefficients of the dual fluid, which also obeys an interesting and exact constraint on its stress tensor. We propose novel Lagrangian models which realise key properties of the holographic fluid.Comment: 31 pages; v2: references added and minor improvements, published versio