Mode shaping in mixed ion crystals of 40Ca2+ and 40Ca+

Feldker, T.; Pelzer, Lennart; Stappel, Matthias; Bachor, P.; Steinborn, R.; Kolbe, Daniel; Walz, J.; Schmidt‐Kaler, F.

doi:10.1007/s00340-013-5673-1

Cited by 10 publications

(16 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Trap (A) consists of four cylindrical rods with diameter d = 2.5 mm at a diagonal distance of 2.2 mm, and two endcaps at a distance of 10 mm [9,21]. It has a rather large trapping volume and features stable ion trapping at very low field gradients.…”

mentioning

confidence: 99%

Rydberg Excitation of a Single Trapped Ion

et al. 2015

Self Cite

View full text Add to dashboard Cite

We demonstrate excitation of a single trapped cold 40 Ca + ion to Rydberg levels by laser radiation in the vacuum-ultraviolet at 122 nm wavelength. Observed resonances are identified as 3d 2 D 3/2 to 51 F, 52 F and 3d 2 D 5/2 to 64 F. We model the lineshape and our results imply a large state-dependent coupling to the trapping potential. Rydberg ions are of great interest for future applications in quantum computing and simulation, in which large dipolar interactions are combined with the superb experimental control offered by Paul traps.PACS numbers: 37.10. Ty, 32.80.Ee, 42.50.Ex The properties of Rydberg atoms are dominated by one electron being in a state of high principal quantum number, which causes long lifetimes and large dipole moments [1,2]. This results in giant dipolar interactions between Rydberg atoms [3] which enable the formation of ultralong-range molecules [4], quantum logic gate operations between two neutral atoms [5,6], and the control of the state of transmitted light through a Rydberg sample at the single photon level [7]. A completely new approach to this field of research is the Rydberg excitation of trapped ions [8,9,10], which aims to combine the long-range Rydberg-blockade mechanism, demonstrated in the case of neutral atoms confined in optical lattices [11,12,13], with the superb level of control over single ions achieved in Paul traps [14,15]. Rydberg ions in Coulomb crystals will allow for shaping localized vibrational modes for quantum simulation and fast parallel execution of quantum gates [16,17]. Further applications are dynamical structural phase transitions and non-equilibrium dynamics driven by Rydberg excitations [18].Two major challenges have to be met in order to access the unique features of Rydberg ions: Firstly, excitation energies are large compared to the case of neutral atoms such that either a vacuum ultraviolet (VUV) laser source [9,19] or multi-step excitation [20] with UV lasers is required. Secondly, the large polarizability of Rydberg states makes them very susceptible to residual electric fields in the Paul trap, where an oscillating field with quadrupolar geometry and gradients of about 10 7 -10 9 V/m 2 provides stable trapping conditions. Ions are confined near the node (field-zero) of the electric quadrupole, nevertheless residual fields at the position of the ion perturb the Rydberg state and lead to a shifted and broadened resonance.In this Letter we present laser excitation of a single trapped cold ion to Rydberg states. Ions are initialized in the metastable 3d 2 D 3/2 or 3d 2 D 5/2 state before they are excited to the 51 F and 52 F (from D 3/2 ) respectivly 64 F (from D 5/2 ) state using vacuum ultraviolet radiation near 122 nm. By applying a state dependent fluorescence measurement following the decay of the Rydberg state, population transfer out of the initial D-state is detected. The polarizability of the Rydberg ion is deduced from the observed line-shift and -broadening, caused by residual electric fields in the trap.Experiments were carried o...

show abstract

mentioning

confidence: 99%

Rydberg Excitation of a Single Trapped Ion

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Similar mode shaping has been experimentally demonstrated using e.g. doubly charged impurity ions in ion crystals [66], which however do not allow tunability. In our case, the effect arrises by the internal state of the central plaquette ion interacting with the pinning laser field.…”

Section: Double Hexagonal Plaquette In An N = 19 Ion Crystalmentioning

confidence: 62%

Hexagonal plaquette spin–spin interactions and quantum magnetism in a two-dimensional ion crystal

et al. 2015

View full text Add to dashboard Cite

We propose a trapped ion scheme en route to realize spin Hamiltonians on a Kagome lattice which, at low energies, are described by emergent  2 gauge fields, and support a topological quantum spin liquid ground state. The enabling element in our scheme is the hexagonal plaquette spin-spin interactions in a two-dimensional ion crystal. For this, the phonon-mode spectrum of the crystal is engineered by standing-wave optical potentials or by using Rydberg excited ions, thus generating localized phonon-modes around a hexagon of ions selected out of the entire two-dimensional crystal. These tailored modes can mediate spin-spin interactions between ion-qubits on a hexagonal plaquette when subject to state-dependent optical dipole forces. We discuss how these interactions can be employed to emulate a generalized Balents-Fisher-Girvin model in minimal instances of one and two plaquettes. This model is an archetypical Hamiltonian in which gauge fields are the emergent degrees of freedom on top of the classical ground state manifold. Under realistic situations, we show the emergence of a discrete Gauss's law as well as the dynamics of a deconfined charge excitation on a gauge-invariant background using the two-plaquettes trapped ions spin-system. The proposed scheme in principle allows further scaling in a future trapped ion quantum simulator, and we conclude that our work will pave the way towards the simulation of emergent gauge theories and quantum spin liquids in trapped ion systems.

show abstract

“…All terms up to second order can be brought into diagonal form by a generalized unitary (Bogoliubovtype) transformation. The higher order terms H ∆ = ∞ m=3 H (m) subsequently describe possible phonon interactions and decay processes, discussed for instance in [41,43,47].…”

Section: General Phonon Transformation On the Operator Levelmentioning

confidence: 99%

“…Also in the context of digital quantum computation with trapped ions [38,39], where the qubits are typically encoded in the ions' hyperfine states, the phonon modes provide the bus via which information can be exchanged and are essential in the realization of single-and two-qubit gates. A detailed understanding of the phononic structure in ion systems is therefore important for the research directions discussed above [40][41][42][43]. In this work we provide an alternative method to calculate the phonon structure compared to established ones [10,[40][41][42], where one determines the collective eigenmodes of the classical system and subsequently quantizes these.…”

Section: Introductionmentioning

confidence: 99%

Operator-based derivation of phonon modes and characterization of correlations for trapped ions at zero and finite temperature

2016

View full text Add to dashboard Cite

We present a self-contained operator-based approach to derive the spectrum of trapped ions. This approach provides the complete normal form of the low-energy quadratic Hamiltonian in terms of bosonic phonons, as well as an effective free-particle degree of freedom for each spontaneously broken spatial symmetry. We demonstrate how this formalism can directly be used to characterize an ion chain both in the linear and the zigzag regimes. In particular, we compute, both for the ground state and finite temperature states, spatial correlations, heat capacity, and dynamical susceptibility. Last, for the ground state, which has quantum correlations, we analyze the amount of energy reduction compared to an uncorrelated state with minimum energy, thus highlighting how the system can lower its energy by correlations.

show abstract

Mode shaping in mixed ion crystals of 40Ca2+ and 40Ca+

Abstract: We present studies of mixed

Cited by 10 publications

References 25 publications

Rydberg Excitation of a Single Trapped Ion

Rydberg Excitation of a Single Trapped Ion

Hexagonal plaquette spin–spin interactions and quantum magnetism in a two-dimensional ion crystal

Operator-based derivation of phonon modes and characterization of correlations for trapped ions at zero and finite temperature

Contact Info

Product

Resources

About