Quantum conditional operations

Conditional Density Operators and the Subjectivity of Quantum Operations

Assuming that quantum states, including pure states, represent subjective degrees of belief rather than objective properties of systems, the question of what other elements of the quantum formalism must also be taken as subjective is addressed. In particular, we ask this of the dynamical aspects of the formalism, such as Hamiltonians and unitary operators. Whilst some operations, such as the up...

Quantum Conditional Probabilities Are Not Probabilities of Quantum Conditional

Stabilizer states, conditional Clifford operations, and their possible role in quantum computation

We work with the following (fairly standard) setting for quantum computation. The computer consists of n qudits, i.e. quantum systems with a d-dimensional Hilbert space. We will mostly focus on qubits (d = 2) but most of the theory can be generalized for d prime and we are working on generalizations for general values of d. The initial state is a basis state reflecting the classical input (poss...

Local and Conditional Blackboard Operations in

This paper discusses two extensions to the kernel Log language presented in 11]: local blackboards and conditional access primitives. The former are needed to alleviate the blackboard communication bottleneck and to solve message naming connicts whereas the latter improves the message selection power of pattern matching or uniication. We propose a syntax for both extensions, give their operatio...

Quantum conditional query complexity

We define and study a new type of quantum oracle, the quantum conditional oracle, which provides oracle access to the conditional probabilities associatedwith an underlying distribution. Amongst other properties, we (a) obtain speed-ups over the best known quantum algorithms for identity testing, equivalence testing and uniformity testing of probability distributions; (b) study the power of the...