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

# All

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.