# The binegativity of two qubits

## TL;DR

This paper introduces the binegativity, a new entanglement measure for two-qubit states, which may offer novel insights into the structure of entanglement beyond existing measures like concurrence and negativity.

## Contribution

The paper proposes the binegativity as a new entanglement measure and compares its ordering of states to existing measures, supported by numerical evidence.

## Key findings

- Binegativity is conjectured to be an entanglement measure.
- It induces a different ordering of two-qubit states compared to known measures.
- Numerical evidence supports the properties of binegativity.

## Abstract

We introduce an entanglement-related quantity that we call the binegativity. Based on numerical evidence, we conjecture that the binegativity is an entanglement measure for two-qubit states. The binegativity is compared to the concurrence and negativity, the only known entanglement measures that can be computed analytically for all two-qubit states. The ordering of entangled two-qubit mixed states induced by the binegativity is distinct from the ordering determined by previously known measures, yielding possible new insights into the structure of entangled two-qubit mixed states.