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Reduction of heating rate in a microfabricated ion trap by pulsedlaser cleaning
"... Abstract. Lasercleaning of the electrodes in a planar microfabricated ion trap has been attempted using ns pulses from a tripled Nd:YAG laser at 355nm. The effect of the laser pulses at several energy density levels has been tested by measuring the heating rate of a single 40Ca+ trapped ion as a f ..."
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Abstract. Lasercleaning of the electrodes in a planar microfabricated ion trap has been attempted using ns pulses from a tripled Nd:YAG laser at 355nm. The effect of the laser pulses at several energy density levels has been tested by measuring the heating rate of a single 40Ca+ trapped ion as a function of its secular frequency ωz. A reduction of the electricfield noise spectral density by ∼ 50 % has been observed and a change in the frequency dependence also noticed. This is the first reported experiment where the “anomalous heating ” phenomenon has been reduced by removing the source as opposed to reducing its thermal driving by cryogenic cooling. This technique may open the way to better control of the electrode surface quality in ion microtraps. ar
Testing Bell’s Inequality with Ballistic Electrons in Semiconductors
, 2000
"... We propose an experiment to test Bell’s inequality violation in condensedmatter physics. We show how to generate, manipulate and detect entangled states using ballistic electrons in Coulombcoupled semiconductor quantum wires. Due to its simplicity (only five gates are required to prepare entangled ..."
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We propose an experiment to test Bell’s inequality violation in condensedmatter physics. We show how to generate, manipulate and detect entangled states using ballistic electrons in Coulombcoupled semiconductor quantum wires. Due to its simplicity (only five gates are required to prepare entangled states and to test Bell’s inequality), the proposed semiconductorbased scheme can be implemented with currently available technology. Moreover, its basic ingredients may play a role towards largescale quantuminformation processing in solidstate devices.
Spin Electronics and Spin Computation
, 2001
"... We review several proposed spintronic devices that can provide new functionality or improve available functions of electronic devices. In particular, we discuss a high mobility field effect spin transistor, an allmetal spin transistor, and our recent proposal of an allsemiconductor spin transistor ..."
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We review several proposed spintronic devices that can provide new functionality or improve available functions of electronic devices. In particular, we discuss a high mobility field effect spin transistor, an allmetal spin transistor, and our recent proposal of an allsemiconductor spin transistor and a spin battery. We also address some key issues in spinpolarized transport, which are relevant to the feasibility and operation of hybrid semiconductor devices. Finally, we discuss a more radical aspect of spintronic research—the spinbased quantum computation and quantum information processing. I.
Quantum Information Processing and Quantum Control with Trapped Atomic Ions
 Phys. Scr. 2009
"... The role of trapped atomic ions in the field of quantum information processing is briefly reviewed. We discuss some of the historical developments that enabled ions to enter the field and then summarize the basic mechanisms required for logic gates and the use of the gates in demonstrating simple al ..."
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The role of trapped atomic ions in the field of quantum information processing is briefly reviewed. We discuss some of the historical developments that enabled ions to enter the field and then summarize the basic mechanisms required for logic gates and the use of the gates in demonstrating simple algorithms. We describe potential pathways to reach faulttolerant error levels and largescale devices, and highlight some of the main problems that will be faced in achieving these goals. Possible nearterm applications in applied and basic science, such as in metrology and quantum simulation, are discussed. PACS numbers: 03.67.−a, 03.67.Ac, 37.10.Ty (Some figures in this article are in colour only in the electronic version.) 1.
Distributed Hybrid Quantum Computing
, 2008
"... There are numerous proposals for the physical realization of a quantum computer. However, distributed approaches, making use both of flying and stationary qubits, seem to constitute the most promising route towards a truly scalable device. Such systems guarantee extendibility, they incorporate the i ..."
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There are numerous proposals for the physical realization of a quantum computer. However, distributed approaches, making use both of flying and stationary qubits, seem to constitute the most promising route towards a truly scalable device. Such systems guarantee extendibility, they incorporate the interface with communication applications and relax the physical realization of the device, allowing for defect tolerance. Flying qubits are included in the more general concept of a quantum bus, a mediating system which can be of higher dimension. Such a quantum bus can be used in the straightforward preparation of a standard multiqubit resource enabling measurement based quantum computation, the cluster state. This constitutes the framework for the results presented in this thesis. We begin by investigating the effects of dissipation in the continuous variable bus scheme known as the qubus scheme. By considering loss in the bus as it mediates interactions between the stationary qubits, we obtain analytical results for the effective action of the induced quantum gate. We find
Verified Delegated Quantum Computing with One Pure Qubit
, 2014
"... While building a universal quantum computer remains challenging, devices of restricted power such as the socalled one pure qubit model have attracted considerable attention. An important step in the construction of these limited quantum computational devices is the understanding of whether the ver ..."
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While building a universal quantum computer remains challenging, devices of restricted power such as the socalled one pure qubit model have attracted considerable attention. An important step in the construction of these limited quantum computational devices is the understanding of whether the verification of the computation within these models could be also performed in the restricted scheme. Encoding via blindness (a cryptographic protocol for delegated computing) has proven successful for the verification of universal quantum computation with a restricted verifier. In this paper, we present the adaptation of this approach to the one pure qubit model, and present the first feasible scheme for the verification of delegated one pure qubit model of quantum computing. 1
QUANTUM SIMULATION IN STRONGLY CORRELATED OPTICAL LATTICES
, 2012
"... An outstanding problem in physics is how to understand strongly interacting quantum manybody systems such as the quarkgluon plasma, neutron stars, superfluid 4He, and the hightemperature superconducting cuprates. The physics approach to this problem is to reduce these complex systems to minimal m ..."
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An outstanding problem in physics is how to understand strongly interacting quantum manybody systems such as the quarkgluon plasma, neutron stars, superfluid 4He, and the hightemperature superconducting cuprates. The physics approach to this problem is to reduce these complex systems to minimal models that are believed to retain relevant phenomenology. For example, the Hubbard model — the focus of this thesis — describes quantum particles tunneling between sites of a lattice with onsite interactions. The Hubbard model is conjectured to describe the lowenergy charge and spin properties of hightemperature superconducting cuprates. Thus far, there are no analytic solutions to the Hubbard model, and numerical calculations are difficult and even impossible in some regimes (e.g., the FermiHubbard model away from halffilling). Therefore, whether the Hubbard model is a minimal model for the cuprates remains unresolved. In the face of these difficulties, a new approach has emerged — quantum simulation. The premise of quantum simulation is to perform experiments on a quantum system that is welldescribed by the model we are trying to study, has tunable parameters, and is easily probed. Ultracold atoms trapped in optical lattices are an ideal candidate for quantum simulation of the Hubbard models. This thesis describes work on two such systems: a 87Rb (boson) optical lattice experiment in the group of Brian DeMarco at the University