Universal properties of a critical quantum spin chain are encoded in the
underlying conformal field theory (CFT). This underlying CFT is fully
characterized by its conformal data. We propose a method to extract the
conformal data from a critical quantum spin chain with both periodic and
anti-periodic boundary conditions (PBC and APBC) based on low-energy
eigenstates, generalizing previous work on spin chains with only PBC. First,
scaling dimensions and conformal spins are extracted from the energies and

The L\"uders rule provides a way to define a quantum channel given a quantum
measurement. Using this construction, we establish an if-and-only-if condition
for the existence of a $d$-dimensional Symmetric Informationally Complete
quantum measurement (a SIC) in terms of a particular depolarizing channel.
Moreover, the channel in question satisfies two entropic optimality criteria.

Quantum algorithms are usually described as monolithic circuits, becoming
large at modest input size. Near-term quantum architectures can only manage a
small number of qubits. We develop an automated method to distribute quantum
circuits over multiple agents, minimising quantum communication between them.
We reduce the problem to hypergraph partitioning and then solve it with
state-of-the-art optimisers. This makes our approach useful in practice, unlike

We present a $2\mathrm{-dimensional}$ quantum walker on curved discrete
surfaces with dynamical geometry. This walker extends the quantum walker over
the fixed triangular lattice introduced in
\cite{quantum_walk_triangular_lattice}. We write the discrete equations of the
walker on an arbitrary triangulation, whose flat spacetime limit recovers the
Dirac equation in (2+1)-dimension. The geometry is changed through Pachner
moves, allowing the surface to transform into any topologically equivalent

The so-called stellar formalism allows to represent the non-Gaussian
properties of single-mode quantum states by the distribution of the zeros of
their Husimi Q-function in phase-space. We use this representation in order to
derive an infinite hierarchy of single-mode states based on the number of zeros
of the Husimi Q-function, the stellar hierarchy. We give an operational
characterisation of the states in this hierarchy with the minimal number of
single-photon additions needed to engineer them, and derive equivalence classes

Blind quantum computation (BQC) allows that a client who has limited quantum
abilities can delegate quantum computation to a server who has advanced quantum
technologies but learns nothing about the client's private information. For
example, measurement-based model can guarantee privacy of client's inputs,
quantum algorithms and outputs. However, it still remains a challenge to
directly encrypt quantum algorithms in circuits model. To solve the problem, we

We propose a practical protocol to generate and observe a non-Abelian
geometric phase using a periodically driven Raman process in the hyperfne
ground state manifold of atoms in a dilute ultracold gas. Our analysis is based
upon recent developments and application of Floquet theory to periodically
driven quantum systems. The simulation results show the non-Abelian gauge
transformation and the non-commuting property of the SU(2) transformation
operators. Based on these results, we propose a possible experimental

Number state filtered coherent states are a class of nonclassical states
obtained by removing one or more number states from a coherent state. Phase
sensitivity of an interferometer is enhanced if these nonclassical states are
used as input states. The optimal phase sensitivity, which is related to the
quantum Cramer-Rao bound (QCRB) for the input state, improves beyond the
standard quantum limit. It is argued that removal of more than one suitable
number state leads to better phase sensitivity. As an important limiting case

As with any quantum computing platform, semiconductor quantum dot devices
require sophisticated hardware and controls for operation. The increasing
complexity of quantum dot devices necessitates the advancement of automated
control software and image recognition techniques for rapidly evaluating charge
stability diagrams. We use an image analysis toolbox developed in Python to
automate the calibration of virtual gates, a process that previously involved a
large amount of user intervention. Moreover, we show that straightforward

We study entanglement of spin degrees of freedom with continuous one in
supersymmetric (SUSY) quantum mechanics. Concurrence is determined by mean
value of spin and is calculated explicitly for SUSY states. We show that
eigenstates of supercharges are maximally entangled. As an example the
entanglement of atom state with photon state and SUSY in Jaynes-Cummings model
are considered.