Research Articles:
Nonlocality, entanglement, and randomness in different conflicting
interest Bayesian games (pp901-934)
Hargeet Kaur and Atul Kumar
We analyse different Bayesian games
where payoffs of players depend on the types of players involved in a
two-player game. The dependence is assumed to commensurate with the CHSH
game setting. For this, we consider two different types of each player
(Alice and Bob) in the game, thus resulting in four different games
clubbed together as one Bayesian game. Considering different
combinations of common interest, and conflicting interest coordination
and anti-coordination games, we find that quantum strategies are always
preferred over classical strategies if the shared resource is a pure
non-maximally entangled state. However, when the shared resource is a
class of mixed state, then quantum strategies are useful only for a
given range of the state parameter. Surprisingly, when all conflicting
interest games (Battle of the Sexes game and Chicken game) are merged
into the Bayesian game picture, then the best strategy for Alice and Bob
is to share a set of non-maximally entangled pure states. We demonstrate
that this set not only gives higher payoff than any classical strategy,
but also outperforms a maximally entangled pure Bell state, mixed Werner
states, and Horodecki states. We further propose the representation of a
special class of Bell inequality- tilted Bell inequality, as a common as
well as conflicting interest Bayesian game. We thereafter, study the
effect of sharing an arbitrary two-qubit pure state and a class of mixed
state as quantum resource in those games; thus verifying that
non-maximally entangled states with high randomness help attain maximum
quantum benefit. Additionally, we propose a general framework of a
two-player Bayesian game for d-dimensions Bell-CHSH inequality, with and
without the tilt factor.
Quantum memory and quantum correlations of Majorana qubits used for
magnetometry
(pp935-956)
H. Rangani Jahromi and S. Haseli
We address how the non-local nature of
the topological
qubits,
realized by
Majorana
modes and driven by an external magnetic field, can be used to
control the non-Markovian
dynamics of the system. It is also demonstrated that the non-local
characteristic plays a key role in control and protection of
quantum correlations between
Majorana
qubits.
Moreover, we discuss how those non-local
qubits
help us to enhance quantum
magnetometry.
(t,n)
Threshold d-level QSS based on QFT
(pp957-968)
Sarbani Roy and Sourav
Mukhopadhyay
Quantum secret sharing (QSS)
is an important branch of secure multiparty quantum computation. Several
schemes for $(n, n)$
threshold QSS based on quantum
Fourier transformation (QFT) have
been proposed. Inspired by the flexibility of
$(t, n)$
threshold schemes, Song {\it
et al.}
(Scientific Reports, 2017) have proposed a
$(t, n)$
threshold QSS
utilizing $QFT$.
Later, Kao and Hwang (arXiv:1803.00216)
have identified a {loophole} in the scheme but have not suggested any
remedy. In this present study, we have proposed a
$(t, n)$
threshold QSS
scheme to share a $d$
dimensional classical secret. This scheme can be implemented using local
operations (such as $QFT$,
generalized Pauli operators and local measurement) and classical
communication. Security of the proposed scheme is described against
outsider and participants' eavesdropping.
A
thermal quantum classifier
(pp969-986)
Ufuk Korkmaz, Deniz Turkpence, Tahir Cetin Akinci, and Serhat Seker
We find that the additivity of quantum
information channels enables one to introduce a quantum classifier or a
quantum decision maker. Proper measurement and sensing of temperature
are of central importance to the realization of nanoscale quantum
devices. Minimal classifiers may constitute the basic units for the
physical quantum neural networks. We introduce a binary temperature
classifier quantum model that operates in a thermal environment. In the
present study, first the mathematical model was introduced through a
two-level quantum system weakly coupled to the thermal reservoirs and it
was demonstrated that the model faithfully classifies the temperature
information of the reservoirs in the thermal steady state limit. A
physical model by superconducting circuits composed of transmon qubits
was also suggested.