66 research outputs found
Asymmetric Quantum Dialogue in Noisy Environment
A notion of asymmetric quantum dialogue (AQD) is introduced. Conventional
protocols of quantum dialogue are essentially symmetric as both the users
(Alice and Bob) can encode the same amount of classical information. In
contrast, the scheme for AQD introduced here provides different amount of
communication powers to Alice and Bob. The proposed scheme, offers an
architecture, where the entangled state and the encoding scheme to be shared
between Alice and Bob depends on the amount of classical information they want
to exchange with each other. The general structure for the AQD scheme has been
obtained using a group theoretic structure of the operators introduced in
(Shukla et al., Phys. Lett. A, 377 (2013) 518). The effect of different types
of noises (e.g., amplitude damping and phase damping noise) on the proposed
scheme is investigated, and it is shown that the proposed AQD is robust and
uses optimized amount of quantum resources.Comment: 11 pages, 2 figure
A novel two-party semiquantum key distribution protocol based on GHZ-like states
In this paper, we propose a novel two-party semiquantum key distribution
(SQKD) protocol by only employing one kind of GHZ-like state. The proposed SQKD
protocol can create a private key shared between one quantum party with
unlimited quantum abilities and one classical party with limited quantum
abilities without the existence of a third party. The proposed SQKD protocol
doesn't need the Hadamard gate or quantum entanglement swapping. Detailed
security analysis turns out that the proposed SQKD protocol can resist various
famous attacks from an outside eavesdropper, such as the Trojan horse attacks,
the entangle-measure attack, the double CNOT attacks, the measure-resend attack
and the intercept-resend attack.Comment: 15 pages, 2 figures, 1 tabl
Multiparty semiquantum secret sharing based on d-dimensional single-particle states
In this paper, a multiparty semiquantum secret sharing (MSQSS) protocol based
on d-dimensional single-particle states is put forward, where the secret key
from the sender can be shared among different receivers in such a way that only
all receivers cooperate together can they reveal it. This protocol transmits
the single particles in a tree-type way. Detailed security analysis turns out
that this protocol can successfully resist the outside attack and the
participant attack. The protocol has some strengths: (1) it is suitable for the
d-dimensional system; (2) it uses d-dimensional single-particle states rather
than d-dimensional quantum entangled states as initial quantum resource; (3) it
doesn't employ quantum entanglement swapping or unitary operations.Comment: 9 pages, 1 figure, 1 tabl
Semiquantum secret sharing by using x-type states
In this paper, a semiquantum secret sharing (SQSS) protocol based on x-type
states is proposed, which can accomplish the goal that only when two classical
communicants cooperate together can they extract the shared secret key of a
quantum communicant. Detailed security analysis turns out that this protocol
can resist the participant attack and the outside attack. This protocol has
some merits: (1) it only requires one kind of quantum entangled state as the
initial quantum resource; (2) it doesn't employ quantum entanglement swapping
or unitary operations; and (3) it needn't share private keys among different
participants beforehand.Comment: 18 pages, 1 figure, 3 table
Photonic Hybrid State Entanglement Swapping using Cat State Superpositions
We propose the use of hybrid entanglement in an entanglement swapping protocol, as means of distributing a Bell state with high fidelity to two parties, Alice and Bob. The hybrid entanglement used in this work is described as a discrete variable (Fock state) and a continuous variable (cat state superposition) entangled state. We model equal and unequal levels of photonic loss between the two propagating continuous variable modes, before detecting these states via a projective vacuum-one-photon measurement, and the other mode via balanced homodyne detection. We investigate homodyne measurement imperfections, and the associated success probability of the measurement schemes chosen in this protocol. We show that our entanglement swapping scheme is resilient to low levels of photonic losses, as well as low levels of averaged unequal losses between the two propagating modes, and show an improvement in this loss resilience over other hybrid entanglement schemes using coherent state superpositions as the propagating modes. Finally, we conclude that our protocol is suitable for potential quantum networking applications which require two nodes to share entanglement separated over a distance of 5-10 km when used with a suitable entanglement purification scheme
From Quantum Optics to Quantum Technologies
Quantum optics is the study of the intrinsically quantum properties of light.
During the second part of the 20th century experimental and theoretical
progress developed together; nowadays quantum optics provides a testbed of many
fundamental aspects of quantum mechanics such as coherence and quantum
entanglement. Quantum optics helped trigger, both directly and indirectly, the
birth of quantum technologies, whose aim is to harness non-classical quantum
effects in applications from quantum key distribution to quantum computing.
Quantum light remains at the heart of many of the most promising and
potentially transformative quantum technologies. In this review, we celebrate
the work of Sir Peter Knight and present an overview of the development of
quantum optics and its impact on quantum technologies research. We describe the
core theoretical tools developed to express and study the quantum properties of
light, the key experimental approaches used to control, manipulate and measure
such properties and their application in quantum simulation, and quantum
computing.Comment: 20 pages, 3 figures, Accepted, Prog. Quant. Ele
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