Entropy of Quantum States

Entropy and Quantum States of Tachyon Supertube

We quantize the deformed modes of a single supertube solution with regular profile of circular cross section on the unstable non-BPS D3-branes by using the Minahan-Zwiebach tachyon action. The result is used to count the microstates in an ensemble of supertube with fixed macroscopic quantities of charges QD0, QF1 and angular momentum J . We show that the entropy of the system is proportional to...

Invariant Entropy and Complexity of Quantum States

The concept of entropy is fundamental for many branches of physics and other sciences dealing with systems which reveal a certain degree of complexity and disorder. As stressed in the monograph 1, ‘‘entropy is not a single concept but rather a family of notions". In relation to quantum theory, the mainstream of development is formed by four main overlapping lines. They can be referred to as the...

The Quantum Entropy Cone of Stabiliser States

We investigate the universal linear inequalities that hold for the von Neumann entropies in a multi-party system, prepared in a stabiliser state. We demonstrate here that entropy vectors for stabiliser states satisfy, in addition to the classic inequalities, a type of linear rank inequalities associated with the combinatorial structure of normal subgroups of certain matrix groups. In the 4-part...

The information entropy of quantum mechanical states

– It is well known that a Shannon based definition of information entropy leads in the classical case to the Boltzmann entropy. It is tempting to regard the Von Neumann entropy as the corresponding quantummechanical definition. But the latter is problematic from quantum information point of view. Consequently we introduce a new definition of entropy that reflects the inherent uncertainty of qua...

Dissipative processes, quantum States, and entropy.