Loss of Exchange Symmetry in Multiqubit States under Ising Chain Evolution
Sudha1,2**, B. G. Divyamani1, A. R. Usha Devi3,4
1Department of Physics, Kuvempu University, Shankaraghatta, Shimoga-577 451, India 2DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge, CB3 0WA, UK. 3Department of Physics, Bangalore University, Bangalore-560 056, India 4Inspire Institute Inc., McLean, VA 22101, USA.
Loss of Exchange Symmetry in Multiqubit States under Ising Chain Evolution
Sudha1,2**, B. G. Divyamani1, A. R. Usha Devi3,4
1Department of Physics, Kuvempu University, Shankaraghatta, Shimoga-577 451, India 2DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge, CB3 0WA, UK. 3Department of Physics, Bangalore University, Bangalore-560 056, India 4Inspire Institute Inc., McLean, VA 22101, USA.
摘要Keeping in view of importance of exchange symmetry aspects in studies on spin squeezing of multiqubit states, we show that the one-dimensional Ising Hamiltonian with nearest neighbor interactions does not retain the exchange symmetry of initially symmetric multiqubit states. Specifically we show that among 4−qubit states obeying exchange symmetry, all states except W class (and their linear combination) lose their symmetry under time evolution with Ising Hamiltonian. Attributing the loss of symmetry of the initially symmetric states to rotational asymmetry of the one-dimensional Ising Hamiltonian with more than 3 qubits, we indicate that all N−qubit states (N≥5) obeying permutation symmetry lose their symmetry after time evolution with Ising Hamiltonian.
Abstract：Keeping in view of importance of exchange symmetry aspects in studies on spin squeezing of multiqubit states, we show that the one-dimensional Ising Hamiltonian with nearest neighbor interactions does not retain the exchange symmetry of initially symmetric multiqubit states. Specifically we show that among 4−qubit states obeying exchange symmetry, all states except W class (and their linear combination) lose their symmetry under time evolution with Ising Hamiltonian. Attributing the loss of symmetry of the initially symmetric states to rotational asymmetry of the one-dimensional Ising Hamiltonian with more than 3 qubits, we indicate that all N−qubit states (N≥5) obeying permutation symmetry lose their symmetry after time evolution with Ising Hamiltonian.
Sudha;**;B. G. Divyamani;A. R. Usha Devi;
. Loss of Exchange Symmetry in Multiqubit States under Ising Chain Evolution[J]. 中国物理快报, 2011, 28(2): 20305-020305.
Sudha, **, B. G. Divyamani, A. R. Usha Devi,
. Loss of Exchange Symmetry in Multiqubit States under Ising Chain Evolution. Chin. Phys. Lett., 2011, 28(2): 20305-020305.
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2011, Vol. 28 
