We investigate a time-independent many-boson system,whose ground states are quasi-degenerate and become infinitely degenerate in the thermodynamic limit.Out of these quasi-degenerate ground states we construct a quant...We investigate a time-independent many-boson system,whose ground states are quasi-degenerate and become infinitely degenerate in the thermodynamic limit.Out of these quasi-degenerate ground states we construct a quantum state that evolves in time with a period that is logarithmically proportional to the number of particles,that is,T~log N.This boson system in such a state is a quantum time crystal as it approaches the ground state in the thermodynamic limit.The logarithmic dependence of its period on the total particle number N makes it observable experimentally even for systems with very large number of particles.Possible experimental proposals are discussed.展开更多
基金supported by the National Key R&D Program of China(Grant Nos.2017YFA0303302 and 2018YFA0305602)the National Natural Science Foundation of China(Grant No.11921005)Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)。
文摘We investigate a time-independent many-boson system,whose ground states are quasi-degenerate and become infinitely degenerate in the thermodynamic limit.Out of these quasi-degenerate ground states we construct a quantum state that evolves in time with a period that is logarithmically proportional to the number of particles,that is,T~log N.This boson system in such a state is a quantum time crystal as it approaches the ground state in the thermodynamic limit.The logarithmic dependence of its period on the total particle number N makes it observable experimentally even for systems with very large number of particles.Possible experimental proposals are discussed.
