3 research outputs found
A phononic crystal coupled to a transmission line via an artificial atom
We study a phononic crystal interacting with an artificial atom { a
superconducting quantum system { in the quantum regime. The phononic crystal is
made of a long lattice of narrow metallic stripes on a quatz surface. The
artificial atom in turn interacts with a transmission line therefore two
degrees of freedom of different nature, acoustic and electromagnetic, are
coupled with a single quantum object. A scattering spectrum of propagating
electromagnetic waves on the artificial atom visualizes acoustic modes of the
phononic crystal. We simulate the system and found quasinormal modes of our
phononic crystal and their properties. The calculations are consistent with the
experimentally found modes, which are fitted to the dispersion branches of the
phononic crystal near the first Brillouin zone edge. Our geometry allows to
realize effects of quantum acoustics on a simple and compact phononic crystal
Quantum Regime of a Two-Dimensional Phonon Cavity
The quantum regime in acoustic systems is a focus of recent fundamental
research in the new field of Quantum Acoustodynamics (QAD). Systems based on
surface acoustic waves having an advantage of easy integration in
two-dimensions are particularly promising for the demonstration of novel
effects in QAD and development of novel devices of quantum acousto-electronics.
We demonstrate the vacuum mode of the surface acoustic wave resonator by
coupling it to a superconducting artificial atom. The artificial atom is
implemented into the resonator formed by two Brag mirrors. The results are
consistent with expectations supported by the system model and our
calculations. This work opens the way to map analogues of quantum optical
effects into acoustic systems
Demonstration of a parity-time symmetry breaking phase transition using superconducting and trapped-ion qutrits
Scalable quantum computers hold the promise to solve hard computational
problems, such as prime factorization, combinatorial optimization, simulation
of many-body physics, and quantum chemistry. While being key to understanding
many real-world phenomena, simulation of non-conservative quantum dynamics
presents a challenge for unitary quantum computation. In this work, we focus on
simulating non-unitary parity-time symmetric systems, which exhibit a
distinctive symmetry-breaking phase transition as well as other unique features
that have no counterpart in closed systems. We show that a qutrit, a
three-level quantum system, is capable of realizing this non-equilibrium phase
transition. By using two physical platforms - an array of trapped ions and a
superconducting transmon - and by controlling their three energy levels in a
digital manner, we experimentally simulate the parity-time symmetry-breaking
phase transition. Our results indicate the potential advantage of multi-level
(qudit) processors in simulating physical effects, where additional accessible
levels can play the role of a controlled environment.Comment: 14 pages, 9 figure