A Theory of Spin Squeezing

Speaker Name/Affiliation
Norman Yao / Harvard University
Seminar Type Other
CTQM Theory Colloquium
Location (Room)
Duane Physics Room G126
Event Details & Abstracts

Abstract:  Quantum metrology makes use of structured entanglement to perform measurements with greater precision than would be possible with only classically correlated particles. A paradigmatic example of such entanglement is spin squeezing, which is known to be dynamically generated by the celebrated one-axis-twisting model, corresponding to an all-to-all coupled Ising Hamiltonian. Motivated by recent advances in a variety of quantum simulation platforms, there has been tremendous interest in the possibility of generating spin squeezing via Hamiltonians which do not require all-to-all interactions. This interest has centered on a class of power-law interaction models, corresponding to long-ranged generalizations of the so-called XXZ model. We conjecture that scalable spin squeezing in such models is intimately connected to the presence of finite-temperature, easy-plane ferromagnetism, which arises from the spontaneous breaking of a continuous symmetry.  In particular, we d!
emonstrate that if the temperature of the initial product state is below the ordering temperature for an XY ferromagnet, then the system will exhibit scalable spin squeezing. I will end by discussing some recent efforts toward realizing spin squeezing in two dimensional ensembles of both dipolar interacting Rydberg atoms and solid-state spin defects.


Lunch will be provided at 12:00pm, so please come early to eat mingle and eat lunch before the talk begins.