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The Sending-or-Not-Sending protocol of the twin-field quantum key
distribution (TF-QKD) has its advantage of unconditional security proof under
any coherent attack and fault tolerance to large misalignment error. So far
this is the only coherent-state based TF-QKD protocol that has considered
finite-key effect, the statistical fluctuations. Here we consider the complete
finite-key effects for the protocol and we show by numerical simulation that
the protocol with typical finite number of pulses in practice can produce

Shannon entropy ($S$), Fisher information ($I$) and a measure equivalent to
Fisher-Shannon complexity $(C_{IS})$ of a ro-vibrational state of diatomic
molecules (O$_2$, O$_2^+$, NO, NO$^+$) with generalized Kratzer potential is
analyzed.

Atomically-thin layers of two-dimensional materials can be assembled in
vertical stacks held together by relatively weak van der Waals forces, allowing
for coupling between monolayer crystals with incommensurate lattices and
arbitrary mutual rotation. A profound consequence of using these degrees of
freedom is the emergence of an overarching periodicity in the local atomic
registry of the constituent crystal structures, known as a moir\'e
superlattice. Its presence in graphene/hexagonal boron nitride (hBN) structures

A quantum error correction (QEC) code uses $N_{\rm c}$ quantum bits to
construct one "logical" quantum bits of better quality than the original
"physical" ones. QEC theory predicts that the failure probability $p_L$ of
logical qubits decreases exponentially with $N_{\rm c}$ provided the failure
probability $p$ of the physical qubit is below a certain threshold $p<p_{\rm
th}$. In particular QEC theorems imply that the logical qubits can be made
arbitrarily precise by simply increasing $N_{\rm c}$. In this letter, we search

We study the computational complexity of quantum-mechanical expectation
values of single-particle operators in bosonic and fermionic multi-particle
product states. Such expectation values appear, in particular, in
full-counting-statistics problems. Depending on the initial multi-product
state, the expectation values may be either easy to compute (the required
number of operations scales polynomially with the particle number) or hard to
compute (at least as hard as a permanent of a matrix). However, if we only

There have been several research works on the hidden shift problem, quantum
algorithms for the problem, and their applications. However, all the results
have focused on discrete groups. So, we define a continuous hidden shift
problem on $\mathbb{R}^n$ as an extension of the hidden shift problem, and
construct a quantum computing algorithm for solving this problem efficiently.

We consider a setting where qubits are processed sequentially, and derive
fundamental limits on the rate at which classical information can be
transmitted using quantum states that decohere in time. Specifically, we model
the sequential processing of qubits using a single server queue, and derive
explicit expressions for the capacity of such a `queue-channel.' We also
demonstrate a sweet-spot phenomenon with respect to the arrival rate to the
queue, i.e., we show that there exists a value of the arrival rate of the

Information-based uncertainty measures like Shannon entropy, Onicescu energy
and Fisher information (in position and momentum space) are employed to
understand the effect of \emph{symmetric and asymmetric} confinement in a
quantum harmonic oscillator. Also, the transformation of Hamiltonian into a
dimensionless form gives an idea of the composite effect of force constant and
confinement length ($x_c$). In symmetric case, a wide range of $x_{c}$ has been
taken up, whereas asymmetric confinement is dealt by shifting the minimum of

In order to verify the results of Boson sampling experiments one must be able
to compute the permanent of the associated Hamiltonians. Here we first present
a freely available software package, available in both serial and parallel
versions. As part of the timing runs for this package we set a new world
recored for the matrix order on which a permanent has been computed. We include
specialised functions for matrices of limited bandwidth, which also demonstrate

Starting from the many-body Schr\"odinger equation, we derive a new type of
Lindblad Master equations describing a cyclic exciton/electron dynamics in the
light harvesting complex and the reaction center. These equations resemble the
Master equations for the electric current in mesoscopic systems, and they go
beyond the single-exciton description by accounting for the multi-exciton
states accumulated in the antenna, as well as the charge-separation,
fluorescence and photo-absorption. Although these effects take place on very