15 research outputs found
From linear quantum system graphs to qubit graphs: Heralded generation of graph states
A graph picture of linear quantum systems (LQSs) is introduced in Quantum,
5:611 (2021) and arXiv:2211.04042 (2022) to provide systematic methods for
generating multipartite genuine entanglement with and without postselection. An
intriguing and pertinent question emerges from this approach: Can we find a
shared structure between LQS graphs and qubit graphs, commonly referred to as
graph states? If such a structure can be identified, it can be exploited to
generate graph states with LQSs. Our work presents a partial but noteworthy
answer to this question. Within this research, \emph{we suggest a directed
graph structure, which enables the generation of arbitrary caterpillar graph
states employing heralded schemes in LQSs}. The caterpillar graph states
encompass various useful graph states for one-way quantum computing such as
linear graphs, star graphs, and networks of star graphs. The states generated
through this approach will serve as valuable resource states for arbitrary
graph states with fusion gates.Comment: Comments are welcom
ABJM Amplitudes in U-gauge and a Soft Theorem
We report progress in computing and analyzing all tree amplitudes in ABJM
theory. Inspired by the isomorphism between the orthogonal Grassmannian and the
pure spinor geometries, we adopt a new gauge, called u-gauge, for evaluating
the orthogonal Grassmannian integral for ABJM amplitudes. We carry out the
integral explicitly for the 8-point amplitude and obtain the complete
supersymmetric amplitude. The physical and spurious poles arise from the
integral as expected from on-shell diagrams. We also derive a double scalar
soft theorem of ABJM amplitudes and verify it for known amplitudes.Comment: 35 pages, 6 figures; v2. minor correction
Graph approach to entanglement generation by boson subtractions
Entanglement is at the heart of quantum information science in the
fundamental and practical aspects. A priority for studying and utilizing
entanglement is to find reliable procedures to generate entangled states. In
this work, we propose a graph method to systematically search for schemes that
obtains genuine entanglement in arbitrary -partite boson systems without
postselection. Our physical setup is based on the sculpting protocol, which
converts the bosonic symmetrization into entanglement through an
indeterministic boson subtraction operator. This protocol can be realized
as heralded schemes of many-boson systems. We show that our graph picture of
the sculpting protocol provides an organized strategy to find suitable
sculpting protocols for various genuinely entangled states. We have found
general schemes for qubit -partite GHZ and W states which are much more
efficient than former schemes with sculpting protocol. We also have found a
qudit -partite GHZ state generation scheme, which shows our approach
provides a significantly powerful insight into finding simple solutions for
complicated entangled states. As proof of concept that our theoretical schemes
can be realized in many-boson systems, we propose a Bell state generation
scheme in linear optical systems with polarization qubit encoding and heralded
detections.Comment: REVTeX 4.2, 16 pages, comments are welcom
Quantum circuit simulation of linear optics using fermion to qubit encoding
This work proposes a digital quantum simulation protocol for the linear
scattering process of bosons, which provides a simple extension to partially
distinguishable boson cases. Our protocol is achieved by combining the
boson-fermion correspondence relation and fermion to qubit encoding protocols.
As a proof of concept, we designed quantum circuits for generating the
Hong-Ou-Mandel dip by varying particle distinguishability. The circuits were
verified with the classical and quantum simulations using the IBM Quantum and
IonQ cloud services.Comment: 10 pages, 7 figure