Generation of Dicke States with Phonon-Mediated Multilevel Stimulated Raman Adiabatic Passage

Abstract

We generate half-excited symmetric Dicke states of two and four ions. We use multilevel stimulated Raman adiabatic passage whose intermediate states are phonon Fock states. This process corresponds to the spin squeezing operation and half-excited Dicke states are generated during multilevel stimulated Raman adiabatic passage. This method does not require local access for each ion or the preparation of phonon Fock states. Furthermore, it is robust since it is an adiabatic process. We evaluate the Dicke state using a witness operator and determine the upper and lower bounds of the fidelity without using full quantum tomography.

Aharonov–Bohm effect in the tunnelling of a quantum rotor in a linear Paul trap

“…We experimentally observed the quantum tunnelling of the rotor using a magnetic field of a certain magnitude. The three ions were trapped in a linear Paul trap with normal-mode frequencies of {o x , o y , o z } ¼ 2p  {1.523, 1.961, 1.119} MHz (further details of the experimental system can be found in refs 34,35), and the orientation of the triangular structure could be set using intermediate confinement conditions. Figure 2a shows the time sequence of the experiment, which began with the measurement of the initial state of the triangular structure using a chargecoupled device camera.…”

HeraldedW-state preparation using laser-designed superatoms

“…Higher excited collective states could be prepared using a sequence of probe pulses with different frequencies or by employing adiabatic preparation schemes [37,38]. Due to their multi-particle entanglement, higher excited Dicke states have many applications in metrology [39][40][41] and quantum information science [42,43].…”

Deterministic generation of arbitrary symmetric states and entanglement classes

“…[27], it was shown how to create arbitrary Dicke states in trapped ions, and an experiment was performed in Ref. [28]. The idea there was to first generate a k-phonon motional Fock state of, e.g., the center of mass mode, |k pn , and subsequently to transfer it via adiabatic passage with a red sideband transition to the symmetric Dicke state with k excitations, |D N,k .…”

“…Trapped ions are one of the most controllable quantum systems [17,18] and, nevertheless, a limited set of prototypical entangled states such as W [19] or Greenberger-Horne-Zeilinger (GHZ) [20] states of up to 14 qubits have been achieved [21]. Proposals for symmetric Dicke state generation, but not their superpositions as required for the much larger set of arbitrary symmetric states, have also been put forward [22][23][24][25][26][27][28][29]. An alternative quantum platform, as superconducting quantum circuits, is the most promising solid-state quantum technology [30,31].…”