Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Decoherence (5)
- Glass structure (2)
- Interference in nanostructures (2)
- Resonant transmission (2)
- String (2)
-
- The finite element method (2)
- 6j symbols (1)
- A.c conductivity (1)
- Admittance spectroscopy (1)
- Aharonov-Bohm interferometer (1)
- Alkali halide (1)
- Alkali-halides. (1)
- Angular momenta (1)
- Anodic vacuum arc (1)
- Antireflection coating. (1)
- Auger Cascade (1)
- Beam polarization (1)
- Bell Inequalities (1)
- Bell inequality (1)
- CIGS (1)
- CLIC (1)
- Calabar (1)
- CdS thin films; Spray pyrolysis; Structural characteristics; Electrical and optical properties. (1)
- Charge fluctuations (1)
- Clebsch-Gordan coefficients (1)
- Composite materials (1)
- Computer simulation (1)
- Copper (1)
- Copper vapor plasma (1)
- Coulomb blockade (1)
Articles 31 - 56 of 56
Full-Text Articles in Physical Sciences and Mathematics
Microwave Rotational Components Of The \Nu_9= 1 And \Nu _{10} = 2 Vibrational Modes Of ^{13}Ch_{3}Cch Molecule In The Range 16 -- 50 Ghz, Mohammad Al-Share, J. A. Roberts
Microwave Rotational Components Of The \Nu_9= 1 And \Nu _{10} = 2 Vibrational Modes Of ^{13}Ch_{3}Cch Molecule In The Range 16 -- 50 Ghz, Mohammad Al-Share, J. A. Roberts
Turkish Journal of Physics
Some rotational components have been measured in the ground, the \nu _9 = 1 and the \nu _{10} = 2 vibrational states for ^{13}CH_3CCH isotopic species in the frequency range 16--50 GHz. A set of rotational constants has been determined, which gives the best fit between the observed and the calculated frequencies, for each vibrational state. A Fermi resonance was found between these two states.
Esr Studies Of A Quartz Single Crystal From The Menderes Massif-Turkey, Ülkü Ulusoy
Esr Studies Of A Quartz Single Crystal From The Menderes Massif-Turkey, Ülkü Ulusoy
Turkish Journal of Physics
In a recent work, quartz single crystal extracted from the pegmatitic vein in the Menderes Massif (Western Turkey) was investigated and the most recent geological events of the sample was dated using Al centers by ESR (electron spin resonance) techniques. The estimated age of 1.8 \pm 0.5 My agree with neither the previous age evaluated to be 12 My by using isotopic dating techniques nor the lifetimes of these centers in the sample. It was suggested that the thermal or geothermal stressing history of the metamorphic region must have changed the apparent ESR age several cycles in this period. The …
Photoelectrochemical Properties Of Cdse:Sb Thin Film Based Solar Cells: Influence Of Electrode Thickness, Elahipasha U. Masumdar, L. P. Deshmukh
Photoelectrochemical Properties Of Cdse:Sb Thin Film Based Solar Cells: Influence Of Electrode Thickness, Elahipasha U. Masumdar, L. P. Deshmukh
Turkish Journal of Physics
CdSe:Sb (0.1 mol%) thin films of varying thicknesses (423--1838 nm) have been deposited onto the glass and stainless steel substrates in an alkaline medium (pH = 10) using a solution growth technique. The photoelectrochemical activities of these films have been examined using CdSe:Sb (0.1 mol%)/0.25 M NaOH - 0.25M Na_2S- 0.25M S/graphite cell configuration. The films were characterized under illumination of 20 mW/cm^2} intensity to evaluate various cell parameters such as \eta, ff, R_s, R_{sh} etc. It is found that the efficiency \eta and fill factor ff increased from 0.24% to 0.45%, and 51% to 52.9%, respectively, with increase in …
Change Of Birefringence In Dye-Doped Nematic Liquid Crystals Under Laser Illumination, S. Eren San, Oğuz Köysal, Serhat Özder, F. Necati̇ Ecevi̇t
Change Of Birefringence In Dye-Doped Nematic Liquid Crystals Under Laser Illumination, S. Eren San, Oğuz Köysal, Serhat Özder, F. Necati̇ Ecevi̇t
Turkish Journal of Physics
Birefringence property of E7 nematic liquid crystal is investigated via voltage dependent transmittance spectrums. Measurements are performed at wavelength 632.8 nm, which is the absorbance peak of our sample including anthraquinone derivative Disperse Blue 14. Results of dye-doped samples are compared with those undoped for dark and laser illuminated cases. It was observed that birefringence is dependent on laser illumination for dye-doped samples, up to a threshold voltage after which it is constant.
Phase Measurements In Aharonov-Bohm Interferometers, Amnon Aharony, Ora Entin-Wohlman, Yoseph Imry
Phase Measurements In Aharonov-Bohm Interferometers, Amnon Aharony, Ora Entin-Wohlman, Yoseph Imry
Turkish Journal of Physics
In this paper we address measurements of the resonant quantum transmission amplitude t_{QD} = -i t_{QD} e^{i\alpha_{QD}} through a quantum dot (QD), as function of the plunger gate voltage V. Mesoscopic solid state Aharonov-Bohm interferometers (ABI) have been used to measure the ``intrinsic" phase, \alpha_{QD}, when the QD is placed on one of the paths. In a ``closed" interferometer, connected to two terminals, the electron current is conserved, and Onsager's relations require that the conductance G through the ABI is an even function of the magnetic flux \Phi = \hbar c\phi/e threading the ABI ring. Therefore, if one fits G …
Dephasing Of Entangled Electron-Hole Pairs In A Degenerate Electron Gas, J. L. Van Velsen, M. Kindermann, C. W. J. Beenakker
Dephasing Of Entangled Electron-Hole Pairs In A Degenerate Electron Gas, J. L. Van Velsen, M. Kindermann, C. W. J. Beenakker
Turkish Journal of Physics
A tunnel barrier in a degenerate electron gas was recently discovered as a source of entangled electron-hole pairs. Here, we investigate the loss of entanglement by dephasing. We calculate both the maximal violation E_{max} of the Bell inequality and the degree of entanglement (concurrence) C. If the initially maximally entangled electron-hole pair is in a Bell state, then the Bell inequality is violated for arbitrary strong dephasing. The same relation E_{max} = 2 \sqrt{1 + C^2} then holds as in the absence of dephasing. More generally, for a maximally entangled superposition of Bell states, the Bell inequality is satisfied for …
Decoherence In Ballistic Mesoscopic Interferometers, Georg Seelig, Sebastian Pilgram, Markus Büttiker
Decoherence In Ballistic Mesoscopic Interferometers, Georg Seelig, Sebastian Pilgram, Markus Büttiker
Turkish Journal of Physics
We provide a theoretical explanation for two recent experiments on decoherence of Aharonov-Bohm oscillations in two- and multi-terminal ballistic rings. We consider decoherence due to charge fluctuations and emphasize the role of charge exchange between the system and the reservoir or nearby gates. A time-dependent scattering matrix approach is shown to be a convenient tool for the discussion of decoherence in ballistic conductors.
Qce: A Simulator For Quantum Computer Hardware, Kristel Michielsen, Hans De Raedt
Qce: A Simulator For Quantum Computer Hardware, Kristel Michielsen, Hans De Raedt
Turkish Journal of Physics
The Quantum Computer Emulator (QCE) described in this paper consists of a simulator of a generic, general purpose quantum computer and a graphical user interface. The latter is used to control the simulator, to define the hardware of the quantum computer and to debug and execute quantum algorithms. QCE runs in a Windows 98/NT/2000/ME/XP environment. It can be used to validate designs of physically realizable quantum processors and as an interactive educational tool to learn about quantum computers and quantum algorithms. A detailed exposition is given of the implementation of the CNOT and the Toffoli gate, the quantum Fourier transform, …
Adiabatic Quantum Pumping Of Coherent Electrons, Ora Entin-Wohlman, Amnon Aharony, Vyacheslavs Kashcheyevs
Adiabatic Quantum Pumping Of Coherent Electrons, Ora Entin-Wohlman, Amnon Aharony, Vyacheslavs Kashcheyevs
Turkish Journal of Physics
We review recent theoretical calculations of charge transfer through mesoscopic devices in response to slowly-oscillating, spatially-confined, potentials. The discussion is restricted to non-interacting electrons, and emphasizes the role of quantum interference and resonant transmission in producing almost integer values (in units of the electronic charge e) of the charge transmitted per cycle, Q. The expression for the pumped charge is derived from a systematic expansion of the system scattering states in terms of the temporal derivatives of the instantaneous solutions. This yields the effect of the modulating potential on the Landauer formula for the conductance in response to a constant …
Quantum Computing With Electrons On Liquid Helium, İsmai̇l Karakurt
Quantum Computing With Electrons On Liquid Helium, İsmai̇l Karakurt
Turkish Journal of Physics
A quantum computer based on electrons floating over liquid helium is described. Each qubit is made of combinations of ground and first excited states of an electron trapped over micro-electrodes just below the helium surface. We describe mechanisms for preparing the initial state of the qubit, operations with the qubits, and a proposed readout. This system is, in principle, capable of \sim 10^4 operations in a decoherence time, the time in which the wave function collapses.
Au Nanoparticle Clusters: A New System To Model Hopping Conduction, Ç. Kurdak, J. Kim, L. A. Farina, K. M. Lewis, X. Bai, M. P. Rowe, A. J. Matzger
Au Nanoparticle Clusters: A New System To Model Hopping Conduction, Ç. Kurdak, J. Kim, L. A. Farina, K. M. Lewis, X. Bai, M. P. Rowe, A. J. Matzger
Turkish Journal of Physics
We study electrical transport through self-assembled Au nanoparticle clusters which can be viewed as a new model system to study hopping transport. The physics of such systems is governed by two parameters: the charging energy and tunnel coupling between the particles. The charging energy is determined by the size of the nanoparticles. When the diameter of the nanoparticles is less than 4-5 nm the charging energy is large enough that Coulomb blockade effects were observed in electrical transport even at room temperature. The magnitude of the tunnel coupling between the particles was determined by the thiol coating used. To study …
Towards Quantum Communication With Electron Spins, D. S. Saraga, G. Burkard, J. C. Egues, H. A. Engel, P. Recher, Daniel Loss
Towards Quantum Communication With Electron Spins, D. S. Saraga, G. Burkard, J. C. Egues, H. A. Engel, P. Recher, Daniel Loss
Turkish Journal of Physics
We review our recent work towards quantum communication in a solid-state environment with qubits carried by electron spins. We propose three schemes to produce spin-entangled electrons, where the required separation of the partner electrons is achieved via Coulomb interaction. The non-product spin-states originate either from the Cooper pairs found in a superconductor, or in the ground state of a quantum dot with an even number of electrons. In a second stage, we show how spin-entanglement carried by a singlet can be detected in a beam-splitter geometry by an increased (bunching) or decreased (antibunching) noise signal. We also discuss how a …
First Principles Modeling Of Nanostructures, Serdar Öğüt
First Principles Modeling Of Nanostructures, Serdar Öğüt
Turkish Journal of Physics
Among the various theoretical tools for investigating microscopic material properties, ab initio (first principles) methods based on density functional theory and pseudopotentials have had a very good track record over the last two decades in terms of accuracy, reliability, and efficiency. The application of these methods to nanostructures to investigate their structural, electronic, and optical properties has, however, not been quite straightforward due to the large computational demand and new physics inherent in the nanometer and sub-nanometer size region. One particularly useful extension to overcome the computational demand imposed by localized nanostructures has been the introduction of methods based on …
Quantum State Generation And Entanglement Manipulation Using Linear Optics, Şahi̇n Kaya Özdemi̇r, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto
Quantum State Generation And Entanglement Manipulation Using Linear Optics, Şahi̇n Kaya Özdemi̇r, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto
Turkish Journal of Physics
Quantum information processing (QIP) requires unitary operations, measurements and synthesis, manipulation and characterization of arbitrary quantum states. Linear optics provides efficient tools for these purposes. In this review paper, we introduce the elements of linear optics toolbox, and briefly discuss some experimental and theoretical investigations using this toolbox. Our main focus will be the qubit state generation and entanglement extraction using linear optics toolbox.
Orbital Entanglement And Violation Of Bell Inequalities In The Presence Of Dephasing, P. Samuelsson, Eugene Sukhorukov, Markus Büttiker
Orbital Entanglement And Violation Of Bell Inequalities In The Presence Of Dephasing, P. Samuelsson, Eugene Sukhorukov, Markus Büttiker
Turkish Journal of Physics
We discuss orbital entanglement in mesoscopic conductors, focusing on the effect of dephasing. The entanglement is detected via violation of a Bell Inequality formulated in terms of zero-frequency current correlations. Following closely the recent work by Samuelsson, Sukhorukov and Büttiker [1], we investigate how the dephasing affects the possibility to violate the Bell Inequality and how system parameters can be adjusted for optimal violation.
Mesoscopic D-Wave Qubits: Can High-T_C Cuprates Play A Role In Quantum Computing?, Alexandre M. Zagoskin
Mesoscopic D-Wave Qubits: Can High-T_C Cuprates Play A Role In Quantum Computing?, Alexandre M. Zagoskin
Turkish Journal of Physics
Due to nontrivial orbital pairing symmetry, surfaces and interfaces of high-T_c superconductors support states which violate time-reversal (T-) symmetry. Such naturally degenerate states, useful as working states of a qubit, are standard for atomic or molecular-size qubit prototypes (e.g. based on nuclear spins), but exceptional for mesoscopic qubits. (In particular, they hold promise of a better scalability.) In these lectures I review the physics of T-breaking on surfaces and interfaces of high-T_c superconductors; then describe existing proposals for high-T_c based qubits and the current state of experiments; finally, I discuss the decoherence sources in the system, open questions, and future …
Preparation And Optimization Of High Quality Tin Films, Özlem Duyar, Cengi̇z Koçum, H. Zafer Durusoy
Preparation And Optimization Of High Quality Tin Films, Özlem Duyar, Cengi̇z Koçum, H. Zafer Durusoy
Turkish Journal of Physics
TiN thin films have been deposited by DC reactive magnetron sputtering method on glass substrates. The effects of the substrate temperature and the substrate bias voltage on the structural, optical and electrical properties of the films were studied by using XRD, STM, optical transmission and resistivity measurements. The bias voltage was varied in the 0 to 200 V range for two substrate temperatures, 100 °C and 300 °C. The results showed that the substrate bias voltage influenced the stoichiometry and structure of the films. The smoothest and least porous TiN films were prepared at about 160 V substrate bias voltage …
Structural, Electrical And Spectral Studies On Double Rare-Earth Orthoferrites La_{1-X}Nd_Xfeo_3, O.M. Hemeda, Mohsen Mohamed Barakat, D. M. Hemeda
Structural, Electrical And Spectral Studies On Double Rare-Earth Orthoferrites La_{1-X}Nd_Xfeo_3, O.M. Hemeda, Mohsen Mohamed Barakat, D. M. Hemeda
Turkish Journal of Physics
Samples of double rare-earth ferrite La_{1-x}Nd_xFeO_3 are synthesized by a high-temperature double sintering ceramic technique. X-ray diffraction shows that all compounds have an orthorhombic structure. The values of lattice parameter and the volume of the unit cell, changes with increasing Nd^{3+} content. The Goldschmidt tolerance factor decreases and goes far from unity with increasing Nd content. The samples containing Nd ions with x = 0.1, 0.2 and 0.3 have higher resistivity than that of LaFeO_{3}, but for x \ge 0.4 the resistivity decreases. The results indicate the presence of extrinsic semiconducting properties up to 100 °C above which the hopping …
Physical Properties Of Spray Pyrolysed Cds Thin Films, A. Ashour
Physical Properties Of Spray Pyrolysed Cds Thin Films, A. Ashour
Turkish Journal of Physics
Cadmium sulphide (CdS) thin films were prepared by chemical spray-pyrolysis technique. Cleaned glass substrates were used. The substrate temperature was varied in the range 200 -- 400 °C and seems to be one of the more important parameters affecting the physical properties of the semiconductor. The films were characterized by X-ray diffraction (XRD). XRD patterns indicated the presence of single-phase hexagonal CdS. The resistivity of the as-deposited films was found to vary in the range 10^3 - 10^5 \Omega. Cm, depending on the substrate temperature. Direct band gap values of 2.39--2.42 eV were obtained from optical absorption measurements.
Growth Mechanism And Some Properties Of Cd_{1-X}Mn_X Se Semimagnetic Semiconductor Thin Films, V. S. Karande, S. H. Mane, Vithal Bhivaba Pujari, L. P. Deshmukh
Growth Mechanism And Some Properties Of Cd_{1-X}Mn_X Se Semimagnetic Semiconductor Thin Films, V. S. Karande, S. H. Mane, Vithal Bhivaba Pujari, L. P. Deshmukh
Turkish Journal of Physics
(Cd, Mn) Se dilute semiconductor or semimagnetic semiconductors have recently became the focus of intense research due to their interesting combination of magnetic and semiconducting properties, and are employed in a variety of devices including solar cells, gas sensors etc. A series of thin films of this material, Cd_{1 - x}Mn_xSe (0 \le x \le 0.5), were therefore synthesized onto precleaned amorphous glass substrates using a solution growth technique. The sources of cadmium (Cd^{2+}) and manganese (Mn^{2+}) were aqueous solutions of cadmium sulphate and manganese sulphate, and selenium (Se^{2-}) was extracted from a reflux of sodium selenosulphite. The different deposition …
Studies On The Opto-Electronic Constants Of Alkali-Halide Crystals, Mahmoud A. Salem
Studies On The Opto-Electronic Constants Of Alkali-Halide Crystals, Mahmoud A. Salem
Turkish Journal of Physics
In this presentation, the correlation between refractive index n of alkali-halide crystals and both energy band gap E_{g} and Pauling's electronegativity difference \Delta x have been studied. The following relations are proposed for estimating the refractive index n: n^2 + C = A / E_{g} ^{1 / 2} and n^2 + C = E / (\Delta x)^{0.425}, where A, C and E are numerical constants. In addition, an interrelation between the energy band gap E_{g} and electronegativity difference \Delta x has been also proposed. The proposed relation is E_g = 4.45 (\Delta x)^{0.85}. The estimated values of the refractive index …
The Influence Of Ge Content And Annealing Temperature On The D.C And A.C Conductivity Of Ge_{X}Se_{1 - X} Thin Films, Maysoon Faisal Alias, M. N. Makadsi, Z. M. Al-Ajeli
The Influence Of Ge Content And Annealing Temperature On The D.C And A.C Conductivity Of Ge_{X}Se_{1 - X} Thin Films, Maysoon Faisal Alias, M. N. Makadsi, Z. M. Al-Ajeli
Turkish Journal of Physics
Various samples of Ge_{x}Se_{1 - x} system have been prepared for x = 0.05, 0.15& 0.25 in an evacuated quartz tube. Thin films of Ge_{x}Se_{1 - x} film have been prepared via a thermal evaporation method with 350 \pm 5 nm thickness and rate deposition 6 nm/s. The alloy structure and thin films have been examined by X-ray diffraction (XRD). Atomic absorption spectroscopy (AAS) was used to examine the concentration of the composite elements (Ge and Se). The d.c and a.c conductivity of Ge_{x}Se_{1 - x} thin film have been studied as a function of Ge content x and annealing …
Clebsch-Gordan Equalities That Imply The Vanishing Of Particular 6j Symbols, Harry A. Mavromatis
Clebsch-Gordan Equalities That Imply The Vanishing Of Particular 6j Symbols, Harry A. Mavromatis
Turkish Journal of Physics
Three Clebsch-Gordan equalities and three individual Clebsh-Gordan relations are obtained by studying the non-accidental vanishing of certain 6j symbols.
Decoherence In Two Coupled Qubits, Kristian Rabenstein, Dmitri V. Averin
Decoherence In Two Coupled Qubits, Kristian Rabenstein, Dmitri V. Averin
Turkish Journal of Physics
We have developed quantitative description of quantum coherent oscillations in the system of two coupled qubits in the presence of weak decoherence that in general can be correlated between the two qubits. It is shown that in the experimentally realized scheme of excitation of the oscillations, their waveform is not very sensitive to the magnitude of decoherence correlations. Modification of this scheme into potentially useful probe of the degree of decoherence correlations at the two qubits is suggested.
Persistent Currents In Mesoscopic Loops And Networks, Igor O. Kulik
Persistent Currents In Mesoscopic Loops And Networks, Igor O. Kulik
Turkish Journal of Physics
The paper describes persistent (also termed ``permanent", or ``non-decaying") currents in mesoscopic metallic and macromolecular rings, cylinders and networks. The current arises as a response of system to Aharonov-Bohm flux threading the conducting loop and does not require external voltage to support the current. Magnitude of the current is periodic function of magnetic flux with a period of normal-metal flux quantum \Phi_0 = hc/e. Spontaneous persistent currents arise in regular macromolecular structure without the Aharonov-Bohm flux provided the azimuthal periodicity of the ring is insured by strong coupling to periodic background (a ``substrate"), otherwise the system will undergo the Peierls …
Mean Multiplicity Of Quark And Gluon Jets As A Function Of Opening Angle In E^{+}E^{-} \Rightarrow B\Overline{B} G Events, Ayda Beddall
Mean Multiplicity Of Quark And Gluon Jets As A Function Of Opening Angle In E^{+}E^{-} \Rightarrow B\Overline{B} G Events, Ayda Beddall
Turkish Journal of Physics
A comparison of the properties of quark and gluon jets has been madeby Monte Carlo simulation of the reaction Z \rightarrow b \overline{b} g. The jet energy is held fixed for every 5 GeV between 15--30 GeV energies and the mean multiplicity of b-quark and gluon jets are obtained as function of the angle between them. It is seen that the jet properties not only depend on the jet energies but also on the angle between the jets.