Condensed-Matter Physics Seminar: "Quantum technologies with trapped ions: from entangling gates to quantum simulation of interacting spins"

Date: 
Thu, 19/01/201712:00-13:30
Location: 
Danciger B building, Seminar room
Lecturer: Mr. Itsik Cohen
Affiliation: Racah Institute of Physics,
The Hebrew University of Jerusalem
Abstract:
Trapped ions are regarded as one of
the most promising candidates for
quantum information processing, in
which high-fidelity entangling quantum
gates are a crucial element. Although
generating entanglement in laser-
based designs has achieved high
fidelities, the achieved fidelities within
the microwave-based designs have
been less satisfactory due to ambient
magnetic field fluctuations. Utilizing
dynamical decoupling approaches we
propose two protected entangling
gates for the microwave-based
designs. Our first proposal has been
carried out experimentally by Winfried
Hensinger’s group.
Generating entanglement paves a
short path towards quantum simulation
experiments of interacting spins. To
date, trapped ions have mostly been
used to quantum simulate interacting
spin one-half spins, showing the phase
transition from the (anti)ferromagnetic
to paramagnetic phases in the Ising
model and long-range correlation
functions in the XX model. By moving
to integer spin chains, new and subtle
physics can appear; for example, the
local orders vanish and we are left with
hidden orders alone. We have shown
how to generate the XXZ Hamiltonian
for a spin-one chain in trapped ion
systems, and thus to explore the
topological (non-local) Haldane phase.
Recently, Chris Monroe’s group has
built the first quantum simulation of a
spin one chain with trapped ion
system.