Regulation and competition in the Turkish telecommunications industry: an update

This chapter provides an overview of the state of liberalization, competition and regulation of major segments of the telecommunications industry in Turkey. It shows that the competitive stance of the regulatory authority and the development of actual competition has been uneven across segments. Specifically, the degree of competition has been higher in the mobile segment relative to fixed telephony or broadband. The chapter also discusses the new Electronic Communications Law and argues that although not perfect, it provides a coherent basis on which the regulatory authority can pursue competitive objectives in a more even manner. However, the actual development of competition will depend a lot on how the law and the ensuing secondary legislation are actually implemented

Quantum Teleportation from a Propagating Photon to a Solid-State Spin Qubit

The realization of a quantum interface between a propagating photon used for transmission of quantum information, and a stationary qubit used for storage and manipulation, has long been an outstanding goal in quantum information science. A method for implementing such an interface between dissimilar qubits is quantum teleportation, which has attracted considerable interest not only as a versatile quantum-state-transfer method but also as a quantum computational primitive. Here, we experimentally demonstrate transfer of quantum information carried by a photonic qubit to a quantum dot spin qubit using quantum teleportation. In our experiment, a single photon in a superposition state of two colors -- a photonic qubit is generated using selective resonant excitation of a neutral quantum dot. We achieve an unprecedented degree of indistinguishability of single photons from different quantum dots by using local electric and magnetic field control. To teleport a photonic qubit, we generate an entangled spin-photon state in a second quantum dot located 5 meters away from the first and interfere the photons from the two dots in a Hong-Ou-Mandel set-up. A coincidence detection at the output of the interferometer heralds successful teleportation, which we verify by measuring the resulting spin state after its coherence time is prolonged by an optical spin-echo pulse sequence. The demonstration of successful inter-conversion of photonic and semiconductor spin qubits constitute a major step towards the realization of on-chip quantum networks based on semiconductor nano-structures.Comment: 12 pages, 3 figures, Comments welcom

Telecommunications policy reform in Turkey

This paper, considering the economic effects of liberalisation in the telecommunications sector on the Turkish economy, makes use of the empirical studies on the linkages between regulatory regimes and telecommunications prices. Since Turkey is trying to liberalise the telecommunications sector by following the EU approach to liberalisation, the paper considers briefly the regulatory regimes in the telecommunications sectors of the EU and Turkey, determines the ad valorem equivalent of barriers to the telecommunications services sector in Turkey, and derives estimates of the welfare effects of adopting the EU rules and regulations in the Turkish telecommunications sector. It shows that there is tremendous scope for Turkey to benefit from adopting and implementing the legislative, regulatory and institutional framework of the EU telecommunications sector. © 2007 The Authors Journal compilation © 2007 Blackwell Publishing Ltd

Quantum interference of single photons from remote nitrogen-vacancy centers in diamond

We demonstrate quantum interference between indistinguishable photons emitted by two nitrogen-vacancy (NV) centers in distinct diamond samples separated by two meters. Macroscopic solid immersion lenses are used to enhance photon collection efficiency. Quantum interference is verified by measuring a value of the second-order cross-correlation function $g^{(2)}(0) = 0.35 \pm 0.04<0.5$. In addition, optical transition frequencies of two separated NV centers are tuned into resonance with each other by applying external electric fields. Extension of the present approach to generate entanglement of remote solid-state qubits is discussed.Comment: 5 pages, 3 figure

Preface and acknowledgements

[No abstract available

Coherence and control of quantum registers based on electronic spin in a nuclear spin bath

We consider a protocol for the control of few-qubit registers comprising one electronic spin embedded in a nuclear spin bath. We show how to isolate a few proximal nuclear spins from the rest of the environment and use them as building blocks for a potentially scalable quantum information processor. We describe how coherent control techniques based on magnetic resonance methods can be adapted to these electronic-nuclear solid state spin systems, to provide not only efficient, high fidelity manipulation of the registers, but also decoupling from the spin bath. As an example, we analyze feasible performances and practical limitations in a realistic setting associated with nitrogen-vacancy centers in diamond

Turkish population data on the HLA-DQα, LDLR, GYPA, HBGG, D7S8, and GC loci

We have determined the allele and genotype frequencies of six PCR-based genetic markers HLA-DQα, LDLR, GYPA, HBGG, D7S8 and GC in the Turkish population (n = 361 for HLA-DQα, and n = 260 for PM). All loci meet Hardy- Weinberg expectations. The frequency data can be used in forensic analyses in the Turkish population

Resonant enhancement of the zero-phonon emission from a color center in a diamond cavity

We demonstrate coupling of the zero-phonon line of individual nitrogen-vacancy centers and the modes of microring resonators fabricated in single-crystal diamond. A zero-phonon line enhancement exceeding ten-fold is estimated from lifetime measurements at cryogenic temperatures. The devices are fabricated using standard semiconductor techniques and off-the-shelf materials, thus enabling integrated diamond photonics.Comment: 5 pages, 4 figure

Properties of nitrogen-vacancy centers in diamond: group theoretic approach

We present a procedure that makes use of group theory to analyze and predict the main properties of the negatively charged nitrogen-vacancy (NV) center in diamond. We focus on the relatively low temperatures limit where both the spin-spin and spin-orbit effects are important to consider. We demonstrate that group theory may be used to clarify several aspects of the NV structure, such as ordering of the singlets in the ($e^2$) electronic configuration, the spin-spin and the spin-orbit interactions in the ($ae$) electronic configuration. We also discuss how the optical selection rules and the response of the center to electric field can be used for spin-photon entanglement schemes. Our general formalism is applicable to a broad class of local defects in solids. The present results have important implications for applications in quantum information science and nanomagnetometry.Comment: 30 pages, 6 figure