process by coupling the compound lattice
concept and four-beam interference to produce tunable twin motive patterns into a
polymer template, yielding metallic nano
structures with air gaps as low as 7 nm,
approximately 70 times smaller than the
wavelengths of the blue laser light used to
write the features.
The team extended the utility of the
process to form gaps with yields equivalent to that of painstaking serial fabrication methods including focused-ion-beam
milling and electron-beam lithography.
The new method not only is easier and
economical, but also does not need a
cleanroom, according to the researchers.
So far, the technique has yielded 90 per-
cent consistency in the array pattern,
providing the foundation for high-quality,
large-scale superior-quality arrays,
they say.
Universal digital simulator holds promise
for quantum computers
INNSBRUCK, Austria – A new digital
approach enables universal quantum
simulation in a system of trapped ions
that can in principle simulate any physical system efficiently, allowing researchers to explore the dynamics of
quantum computers.
Previously, quantum simulation was
achieved through an analog method:
Two years ago, the research group of
Christian Roos and Rainer Blatt at the
University of Innsbruck re-created the
properties of a particle moving close to
the speed of light in a quantum system.
They encoded the state of the particle
into a highly cooled calcium atom and
used lasers to manipulate it, simulating
the Zitterbewegung (quivering motion)
of relativistic particles, which had
never before been directly observed in
nature.
“Numerical techniques for investi-
gating the dynamics of a quantum sys-
tem are in general limited to simulating
small systems, as the number of pa-
rameters needed for describing the sys-
tem grows exponentially with the sys-
tem size,” Roos said. “For this reason,
it has been proposed to use one quan-
tum system for simulating the physics
of another quantum system to over-
come this limitation.”
In their current work, the mathemati-
cal description of the phenomenon to
be investigated is programmed by
using a series of laser pulses to per-
form quantum calculations with atoms.
Laser-cooled and electrically trapped
calcium atoms are used as carriers of
qubits. They demonstrated the method
in two experiments at the University of
Innsbruck and at the Institute of Quan-
tum Optics and Quantum Information
of the Austrian Academy of Sciences,
using up to 100 gates and six qubits.
