A genuine maximally seven-qubit entangled state

TL;DR

This paper presents a new seven-qubit entangled state that is genuinely maximally entangled, countering previous conjectures by demonstrating specific mixedness properties of its subsystems.

Contribution

The authors construct a seven-qubit state with maximal entanglement properties, challenging prior assumptions about such states.

Findings

The state has completely mixed marginals for 1- and 2-qubit subsystems.

The state has almost completely mixed marginals for 3-qubit subsystems.

It provides a counterexample to previous conjectures on maximally entangled states.

Abstract

Contrary to A.Borras et al.'s [1] conjecture, a genuine maximally seven-qubit entangled state is presented. We find a seven-qubit state whose marginal density matrices for subsystems of 1,2- qubits are all completely mixed and for subsystems of 3-qubits is almost completely mixed.