Almost all multipartite qubit quantum states have trivial stabilizer

The stabilizer group of an n-qubit state |ψ is the set of all matrices of the form g=g1⊗⋯⊗gn, with g1,…,gn being any 2 × 2 invertible complex matrices that satisfy g|ψ=|ψ. We show that for 5 or more qubits, except for a set of states of zero measure, the stabilizer group of multipartite entangled states is trivial, that is, containing only the identity element. We use this result to show that for 5 or more qubits, the action of deterministic local operations and classical communication (LOCC) can almost always be simulated simply by local unitary (LU) operations. This proves that almost all n-qubit states with n≥5 can neither be reached nor be converted into any other (n-partite entangled), LU-inequivalent state via deterministic LOCC. We also find a simple and elegant expression for the maximal probability to convert one multi-qubit entangled state to another for this generic set of states.The stabilizer group of an n-qubit state |ψ is the set of all matrices of the form g=g1⊗⋯⊗gn, with g1,…,gn being any 2 × 2 invertible complex matrices that satisfy g|ψ=|ψ. We show that for 5 or more qubits, except for a set of states of zero measure, the stabilizer group of multipartite entangled states is trivial, that is, containing only the identity element. We use this result to show that for 5 or more qubits, the action of deterministic local operations and classical communication (LOCC) can almost always be simulated simply by local unitary (LU) operations. This proves that almost all n-qubit states with n≥5 can neither be reached nor be converted into any other (n-partite entangled), LU-inequivalent state via deterministic LOCC. We also find a simple and elegant expression for the maximal probability to convert one multi-qubit entangled state to another for this generic set of states.