اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSchrodinger cats and their power for quantum information processing
159
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We outline a toolbox comprised of passive optical elements, single photon detection and superpositions of coherent states (Schrodinger cat states). Such a toolbox is a powerful collection of primitives for quantum information processing tasks. We illustrate its use by outlining a proposal for universal quantum computation. We utilize this toolbox for quantum metrology applications, for instance weak force measurements and precise phase estimation. We show in both these cases that a sensitivity at the Heisenberg limit is achievable.
قيم البحث
اقرأ أيضاً
Quantum optomechanics exploits radiation pressure effects inside optical cavities. It can be used to generate quantum states of the center-of-mass motion of massive mechanical objects, thereby opening up a new parameter regime for macroscopic quantum
experiments. The challenging experimental conditions to maintain and observe quantum coherence for increasingly large objects may require a space environment rather than an earth-bound laboratory. We introduce a possible space experiment to study the wave-packet expansion of massive objects. This forms the basis for Schrodinger cat states of unprecedented size and mass.
Incoherence in the controlled Hamiltonian is an important limitation on the precision of coherent control in quantum information processing. Incoherence can typically be modelled as a distribution of unitary processes arising from slowly varying expe
rimental parameters. We show how it introduces artifacts in quantum process tomography and we explain how the resulting estimate of the superoperator may not be completely positive. We then go on to attack the inverse problem of extracting an effective distribution of unitaries that characterizes the incoherence via a perturbation theory analysis of the superoperator eigenvalue spectra.
We report on the design, fabrication, and preliminary testing of a 150 zone array built in a `surface-electrode geometry microfabricated on a single substrate. We demonstrate transport of atomic ions between legs of a `Y-type junction and measure the
in-situ heating rates for the ions. The trap design demonstrates use of a basic component design library that can be quickly assembled to form structures optimized for a particular experiment.
We demonstrate a SWAP gate between laser-cooled ions in a segmented microtrap via fast physical swapping of the ion positions. This operation is used in conjunction with qubit initialization, manipulation and readout, and with other types of shuttlin
g operations such as linear transport and crystal separation and merging. Combining these operations, we perform quantum process tomography of the SWAP gate, obtaining a mean process fidelity of 99.5(5)%. The swap operation is demonstrated with motional excitations below 0.05(1)~quanta for all six collective modes of a two-ion crystal, for a process duration of 42~$mu$s. Extending these techniques to three ions, we reverse the order of a three-ion crystal and reconstruct the truth table for this operation, resulting in a mean process fidelity of 99.96(13)% in the logical basis.
Based on a multimode multilevel Jaynes-Cummings model and multiphoton resonance theory, a set of universal two- and three-qubit gates, namely the iSWAP and the Fredkin gates, has been realized where dual-rail qubits are encoded in cavities. In this w
ay the information has been stored in cavities and the off-resonant atomic levels have been eliminated by the semi-classical theory of an effective two-level Hamiltonian. A further semi-classical model, namely the spin-$J$ model, has been introduced so that a complete population inversion for levels of interest has been achieved and periodic multilevel multiphoton models have been performed. The combination of the two semi-classical models has been employed to address two-level, three-level, four-level, and even five-level configurations. The impact of decoherence processes on the fidelity of the iSWAP and the Fredkin gates has been studied.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
