Towards scaling up trapped ion quantum information processing

Abstract

Recent theoretical advances have identified several computational algorithms that can be implemented utilizing quantum information processing (QIP), which gives an exponential speedup over the corresponding (known) algorithms on conventional computers. QIP makes use of the counter-intuitive properties of quantum mechanics, such as entanglement and the superposition principle. Unfortunately it has so far been impossible to build a practical QIP system that outperforms conventional computers. Atomic ions confined in an array of interconnected traps represent a potentially scalable approach to QIP. All basic requirements have been experimentally demonstrated in one and two qubit experiments. The remaining task is to scale the system to many qubits while minimizing and correcting errors in the system. While this requires extremely challenging technological improvements, no fundamental roadblocks are currently foreseen.

Scalable, efficient ion-photon coupling with phase Fresnel lenses for large-scale quantum computing

“…Most proposals for large-scale ion-trap quantum computing (QC) envisage the use of a large array of ion traps and the collection of ion fluorescence from many sites of the trap array [9,19,20,21]. Trapping and transport of ions in microfabricated trap arrays is now routine [5] and current trap fabrication technology is suited to the production of extremely large trap arrays [22]. These same sophisticated ion-trap experiments collect ion fluorescence using complex, bulky multi-element objective lenses that must be aligned manually, a technology that is hardly scalable at all.…”

“…Trapped ions have long coherence times, strong yet controllable inter-qubit coupling, and are easy to prepare, manipulate, and read out using established optical and microwave techniques. Many small-scale quantum computation tasks have been demonstrated with trapped ions [4,5,6,7,8] and a roadmap exists for larger scale architectures [9,10,11]. A common thread in all the proposed large scale ion trap quantum computing architectures is the need for a scalable, efficient method for collecting ion fluorescence.…”

Multipole Traps as Tools in Environmental Studies

“…Quantum engineering has opened new perpectives in quantum optics and quantum metrology [28,24]. Applications of ion traps span mass spectrometry, very high precision spectroscopy, quantum physics tests, study of nonneutral plasmas [25,13], quantum information processing (QIP) and quantum metrology [29,16,30,24,20], use of optical transitions in highly charged ions for detection of variations in the fine structure constant [17,20] or very accurate optical atomic clocks [31,32,33,34,35].…”

Implementation of fault-tolerant quantum logic gates via optimal control

“…Many potential physical realizations of quantum computers have been proposed, and although the experimental realization of quantum information processing remains a challenge, there have been many experimental accomplishments including the demonstration of control of multi-qubit dynamics in spin systems using nuclear magnetic resonance techniques [1] and all-optical quantum information processing using photons [2], for instance. While liquid-state NMR and optical quantum computing may suffer from inherent scalability issues, there has also been significant progress in ion-trap architectures and several proposals for making such architectures scalable exist [3,4]. In solid-state systems, successes have been more modest but controlled interactions of quantum dots have been demonstrated in some systems [5,6].…”