Deterministic entanglement generation from driving through quantum phase transitions.
Many-body entanglement is often created through the system evolution, aided by nonlinear interactions between the constituting particles. These very dynamics, however, can also lead to fluctuations and degradation of the entanglement if the interactions cannot be controlled. Here, we demonstrate near-deterministic generation of an entangled twin-Fock condensate of ~11,000 atoms by driving a arubidium-87 Bose-Einstein condensate undergoing spin mixing through two consecutive quantum phase transitions (QPTs). We directly observe number squeezing of 10.7 ± 0.6 decibels and normalized collective spin length of 0.99 ± 0.01. Together, these observations allow us to infer an entanglement-enhanced phase sensitivity of ~6 decibels beyond the standard quantum limit and an entanglement breadth of ~910 atoms. Our work highlights the power of generating large-scale useful entanglement by taking advantage of the different entanglement landscapes separated by QPTs.
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China. lyou@mail.tsinghua.edu.cn mengkhoon_tey@mail.tsinghua.edu.cn.
Xin-Yu
0000-0001-5104-3797
XY
Luo
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China. lyou@mail.tsinghua.edu.cn mengkhoon_tey@mail.tsinghua.edu.cn.
Yi-Quan
0000-0002-5868-1844
YQ
Zou
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China. lyou@mail.tsinghua.edu.cn mengkhoon_tey@mail.tsinghua.edu.cn.
Ling-Na
0000-0003-4722-5883
LN
Wu
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
Qi
0000-0002-7379-9090
Q
Liu
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China.
Ming-Fei
MF
Han
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China. lyou@mail.tsinghua.edu.cn mengkhoon_tey@mail.tsinghua.edu.cn.|Collaborative Innovation Center of Quantum Matter, Beijing, China.
Meng Khoon
0000-0002-4861-527X
MK
Tey
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China. lyou@mail.tsinghua.edu.cn mengkhoon_tey@mail.tsinghua.edu.cn.|Collaborative Innovation Center of Quantum Matter, Beijing, China.
Li
0000-0002-3919-4768
L
You