<i>Colloquium</i>: Trapped ions as quantum bits: Essential numerical tools

Singer, Kilian; Poschinger, Ulrich; Murphy, Michael; Ivanov, Peter A.; Ziesel, Frank; Calarco, Tommaso; Schmidt-Kaler, F.

doi:10.1103/revmodphys.82.2609

Cited by 133 publications

(146 citation statements)

References 113 publications

Supporting

Mentioning

143

Contrasting

Order By: Relevance

“…The results displayed until now are all for systems of eight spins, and this is dictated by the approximate number of spins which can be experimentally accessed coherently in quantum systems. However, such boundaries are steadily being extended and improved [7,8,11,12,[45][46][47][48]. In this light, it is important to mention here that the results obtained in this paper are resilient with respect to moderate changes of the total number of spins.…”

Section: Discussionmentioning

confidence: 86%

“…Technological limitations currently restricts the physically realizable genuinely multiparty entangled quantum states to about 10 qubits [7,8,11,12,45,46]. Moreover, photonic systems are widely envisaged as the substrates for quantum communication protocols, and in that case, currently available technology limitations are even stricter on the number of qubits [47,48].…”

Section: Introductionmentioning

confidence: 99%

“…[6,7], and references therein). And in ion trap systems, where quantum communication protocols can potentially be useful in a future quantum computer realized in that system (see [8][9][10][11][12][13], and references therein).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Disorder overtakes order in information concentration over quantum networks

et al. 2011

View full text Add to dashboard Cite

We consider different classes of quenched disordered quantum XY spin chains, including quantum XY spin glass and quantum XY model with a random transverse field, and investigate the behavior of genuine multiparty entanglement in the ground states of these models. We find that there are distinct ranges of the disorder parameter that gives rise to a higher genuine multiparty entanglement than in the corresponding systems without disorder -an order-from-disorder in genuine multiparty entanglement. Moreover, we show that such a disorder-induced advantage in the genuine multiparty entanglement is useful -it is almost certainly accompanied by a order-from-disorder for a multiport quantum dense coding capacity with the same ground state used as a multiport quantum network.

show abstract

Section: Discussionmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Disorder overtakes order in information concentration over quantum networks

et al. 2011

View full text Add to dashboard Cite

show abstract

“…To assure this, the voltages required for creating a trap minimum with predefined frequency at a given location are calculated a priori. This relation is established using numerically obtained data for the electrostatic trap potentials [13], and has been experimentally verified [14]. The ion used for the experiments is 40 Ca + , where an external magnetic field splits the S 1/2 ground state into two levels, m J = ±1/2, henceforth referred to as |↑ and |↓ .…”

mentioning

confidence: 99%

Controlling Fast Transport of Cold Trapped Ions

et al. 2012

View full text Add to dashboard Cite

We realize fast transport of ions in a segmented micro-structured Paul trap. The ion is shuttled over a distance of more than 10 4 times its groundstate wavefunction size during only 5 motional cycles of the trap (280 µm in 3.6 µs). Starting from a ground-state-cooled ion, we find an optimized transport such that the energy increase is as low as 0.10±0.01 motional quanta. In addition, we demonstrate that quantum information stored in a spin-motion entangled state is preserved throughout the transport. Shuttling operations are concatenated, as a proof-of-principle for the shuttling-based architecture to scalable ion trap quantum computing. . Scalable information processing in a multiplexed ion trap can be accomplished by having fixed processing sites where logic operations are performed, and ion qubits will be moved in and out of these regions by shuttling operations. The duration of such shuttling has to be much faster than the relevant decoherence times [4]. Furthermore, it is desirable to reduce the total time consumption of all relevant operations, where shuttling will contribute a considerable amount [5], and aim for the performance of the naturally fast solid state architectures [6]. So far, ion shuttling in a multiplexed trap has been demonstrated together with additional sympathetic cooling [7], and in the adiabatic regime, where the transient displacement of the ion is smaller than the size of the its wavepacket [8,9]. Transport of neutral atoms have also been performed using magnetic [10] or optical [11] techniques.Because quantum gate operations require ions close to the motional ground state and fast transport inherently creates motional excitation, the challenge is to develop transport protocols that guarantee sufficiency small energy transfer. In this work we demonstrate shuttling operations that are highly non-adiabatic while the final state of the ion is close to the motional groundstate. We also show that quantum information stored in both the motional and the spin degree of freedom is preserved through the shuttling.During a shuttling operation, the ion motion in the harmonic trapping potential is excited when the acceleration is sufficiently strong. This motional excitation is a harmonic oscillation, characterized by a well defined phase, thus allowing it to be canceled out by proper management of the forces involved during or after the transport. We experimentally demonstrate two methods of canceling the acquired motional excitation. One method uses two shuttles, where the transport to the destination generates the same net momentum transfer as the transport back, but is applied 180 • out of phase with respect to the secular oscillation of the ion (Fig. 1b). We refer to this as the pairwise energy-neutral transport. For the second scheme, the self-neutral transport we apply a sharp counter-"kick" to the ion at the end of a single transport operation, stopping its motion (Fig. 1c). This case of single-sided transport allows even faster shuttling and can be sequentially repeated since it is ener...

show abstract

“…A voltage of 1.0 V at this segment will give rise to an electric field of 600 V/m at the initial ion location, which is derived from electrostatic simulation of the trap [26]. This field exerts an acceleration of approximately 1.5·10 9 m/s 2 .…”

Section: Controlled Displacement By Fast Voltage Switchingmentioning

confidence: 99%

Experimental creation and analysis of displaced number states

Ziesel¹,

Ruster²,

Walther³

et al. 2013

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

Abstract. We create displaced number states, which are non-classical generalizations of coherent states, of a vibrational mode of a single trapped ion. The creation of these states is accomplished by a combination of optical and electrical manipulation of the ion. A number state is first prepared by laser-driven climbing of the Jaynes-Cummings ladder, followed by displacement created by a sudden shift of the electrostatic trapping potential. Number states n =0,1 and 2 are prepared, and displacement amplitudes of up to α ≈ 2.8 are reached. The states are analyzed tomographically, and we find a good agreement with the theoretically expected results for displaced number states. Quantum features elucidating the concept of interference in phase space are clearly demonstrated experimentally.

show abstract

Colloquium: Trapped ions as quantum bits: Essential numerical tools

Cited by 133 publications

References 113 publications

Disorder overtakes order in information concentration over quantum networks

Disorder overtakes order in information concentration over quantum networks

Controlling Fast Transport of Cold Trapped Ions

Experimental creation and analysis of displaced number states

Contact Info

Product

Resources

About