3 research outputs found
Non-classical mechanical states guided in a phononic waveguide
The ability to create, manipulate and detect non-classical states of light
has been key for many recent achievements in quantum physics and for developing
quantum technologies. Achieving the same level of control over phonons, the
quanta of vibrations, could have a similar impact, in particular on the fields
of quantum sensing and quantum information processing. Here we present a
crucial step towards this level of control and realize a single-mode waveguide
for individual phonons in a suspended silicon micro-structure. We use a
cavity-waveguide architecture, where the cavity is used as a source and
detector for the mechanical excitations, while the waveguide has a free
standing end in order to reflect the phonons. This enables us to observe
multiple round-trips of the phonons between the source and the reflector. The
long mechanical lifetime of almost 100 demonstrates the possibility of
nearly lossless transmission of single phonons over, in principle, tens of
centimeters. Our experiment demonstrates full on-chip control over traveling
single phonons strongly confined in the directions transverse to the
propagation axis, potentially enabling a time-encoded multimode quantum memory
at telecom wavelength and advanced quantum acoustics experiments
A single-phonon directional coupler
Integrated photonics has enabled countless technologies in
telecommunications, spectroscopy, metrology, quantum optics, and quantum
information processing. Using highly confined guided optical modes is the key
that has made integrated circuits possible and has lead to scaling of complex
designs, benefiting from their small footprint. At the same time, the field of
quantum acoustics has recently gained significant attention due to its various
potential advantages over its photonic counterparts, including smaller mode
volume, lower energy, and orders of magnitude slower propagation speeds, as
well as the potential for interconnecting distinct quantum systems. Developing
analogous integrated phononic technology is critical for realizing the full
potential of phonons and could lead to groundbreaking new applications, such as
scalable quantum computing and hybrid quantum devices. In this work, we
demonstrate for the first time a 4-port directional coupler for quantum
mechanical excitations - a crucial component for integrated phononic circuits.
Adjusting the length of the coupling region allows to realize phononic beam
splitters with varying splitting ratios. By sending a single-phonon Fock state
onto one of these phononic splitters, we demonstrate the capability of using
the directional coupler directly in the quantum regime. Our work provides an
essential step towards an integrated phononic platform for both classical and
quantum technologies applications