Coherent manipulation of the internal state of ultracold ⁸⁷Rb¹³³Cs molecules with multiple microwave fields

Abstract

We explore coherent multi-photon processes in 87Rb133Cs molecules using 3-level lambda and ladder configurations of rotational and hyperfine states, and discuss their relevance to future applications in quantum computation and...

Robust storage qubits in ultracold polar molecules

“…The value of δ 0 indicates the two-photon detuning in free space, and so we determine the free-space energy difference between the states of h × (76 kHz + δ 0 ) = h × 76.983 0(2) kHz. This is in excellent agreement with a calculation from the molecular Hamiltonian which predicts an energy difference between the states of h × 77.0(7) kHz, where the uncertainty results from the current precision with which the strength of the scalar nuclear spin-spin interaction (c 4 ) and the magnitude of the nuclear magnetic moments are known for RbCs [28,29].…”

“…These properties point to the possibility of long-lived coherence and make the nuclear spin states of ultracold polar molecules excellent candidates for robust storage qubits in quantum computing architectures [11,12,25]. In such proposals, gate operations may be performed using dipolar-exchange interactions [15,17] following microwave excitation to an excited rotational state, while single-qubit rotations can be performed using two-photon microwave pulses [26][27][28][29]. Here, we demonstrate coherence times exceeding 6.9 s (90% confidence level) for the storage qubit, paving the way for the use of ultracold molecules as a platform for quantum computation.…”

“…To begin, we seek to identify pairs of nuclear spin states with identical magnetic moments that connect to a common excited rotational state, by calculating the rotational and hyperfine structure of the RbCs molecule in externally applied magnetic and optical fields [28][29][30][31]. We construct the Hamiltonian (see Methods) in a fully uncoupled basis set |N, M N |i Rb , m Rb |i Cs , m Cs , where N represents the angular momentum of the molecule with its projection along the quantisation axis M N , and i Rb = 3/2, i Cs = 7/2 denote the nuclear spins of Rb and Cs respectively, with their projections m Rb , m Cs .…”

Realizing topological edge states with Rydberg-atom synthetic dimensions

“…Because of this mathematical equivalence to particles moving in a real-space lattice, coupled Rydberg levels can function as a synthetic spatial dimension. This scheme, first suggested in 2 , is similar to a proposal for synthetic dimensions based on molecular rotational levels [27][28][29] . It allows for control of the connectivity, tunneling rates, and on-site potentials, and creation of a broad range of synthetic dimensional systems, including systems not realizable in physical space.…”

Magic conditions for multiple rotational states of bialkali molecules in optical lattices

“…In the realm of quantum simulation and computation, the rotational structure of ultracold molecules provides a rich basis of long-lived states in which to encode pseudospins or quantum information. Owing to the permanent molecularframe electric dipole moment, the rotational states can be conveniently manipulated with microwave fields, as already demonstrated in a number of settings [50][51][52][53][54][55]. Moreover, laboratory-frame dipole moments can be engineered using applied electric fields or superpositions of rotational states.…”