It is a recent observation that entanglement classification for qubits is closely related to stochastic local operations and classical communication(SLOCC)invariants.Verstraete et al.[Phys.Rev.A 65(2002)052112]showed ...It is a recent observation that entanglement classification for qubits is closely related to stochastic local operations and classical communication(SLOCC)invariants.Verstraete et al.[Phys.Rev.A 65(2002)052112]showed that for pure states of four qubits there are nine different degenerate SLOCC entanglement classes.Li et al.[Phys.Rev.A 76(2007)052311]showed that there are at least 28 distinct true SLOCC entanglement classes for four qubits by means of the SLOCC invariant and semi-invariant.We give 16 different entanglement classes for four qubits by means of basic SLOCC invariants.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10902083Shaanxi Natural Science Foundation under Contract No 2009JM1007.
文摘It is a recent observation that entanglement classification for qubits is closely related to stochastic local operations and classical communication(SLOCC)invariants.Verstraete et al.[Phys.Rev.A 65(2002)052112]showed that for pure states of four qubits there are nine different degenerate SLOCC entanglement classes.Li et al.[Phys.Rev.A 76(2007)052311]showed that there are at least 28 distinct true SLOCC entanglement classes for four qubits by means of the SLOCC invariant and semi-invariant.We give 16 different entanglement classes for four qubits by means of basic SLOCC invariants.