GUIN-DAR LINMonroe, C.C.MonroeDuan, L.-M.L.-M.Duan2019-12-202019-12-20201100319007https://scholars.lib.ntu.edu.tw/handle/123456789/436905https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960620005&doi=10.1103%2fPhysRevLett.106.230402&partnerID=40&md5=11dd877c73208582eb915395a53698dfSharp quantum phase transitions typically require a large system with many particles. Here we show that, for a frustrated fully connected Ising spin network represented by trapped atomic ions, the competition between different spin orders leads to rich phase transitions whose sharpness scales exponentially with the number of spins. This unusual finite-size scaling behavior opens up the possibility of observing sharp quantum phase transitions in a system of just a few trapped ion spins. © 2011 American Physical Society.Atomic ions; Finite-size scaling behavior; Ising-spin networks; Large system; Quantum phase transitions; Spin order; Trapped ion; Ising model; Phase transitions; Quantum theory; Ionsjournal article10.1103/PhysRevLett.106.2304022-s2.0-79960620005WOS:000291399500001https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960620005&doi=10.1103%2fPhysRevLett.106.230402&partnerID=40&md5=11dd877c73208582eb915395a53698df