Microwave-shielded ultracold molecules

Bose-Fermi dual bound states

These ultracold molecules form universal bound states under a specially shaped microwave field, with properties determined solely by dipolar interaction strength and microwave coupling, applicable to both bosons and fermions.

Shi, Tingting · Wang, Haitian · Cui, Xiaoling

Physical Review Letters 2026

Specifications

Hexatomic bound state binding energy

{'zh': '>2', 'en': '>2'} ×

Advantages

Universal bound states

The bound states depend solely on the strengths of long-range dipolar interaction and microwave coupling, independent of short-range details, so different molecular species can be described by the same theory.

Reduction to 1D

Under a highly elliptic microwave field, few-molecule scatterings in three dimensions are governed by effective one-dimensional (1D) models, which well reproduce the tetratomic bound state and the Born-Oppenheimer potential in three-molecule sector.

Hexatomic deep binding

For hexatomic systems comprising three identical molecules, the binding energy exceeds twice that of the tetratomic state, favoring more stable many-body structures.

Bose-Fermi duality

These bound states display Bose-Fermi duality as facilitated by the effective 1D scattering with a large repulsive core from angular fluctuations.

Applications

• Quantum many-body physics：Unifies bound-state descriptions for bosons and fermions, simplifying many-body theory.
• Quantum simulation：Microwave-shielded ultracold molecules serve as a tunable platform for simulating 1D many-body models.
• Ultracold molecules：Stable bound states are achieved without relying on short-range details.
• Atomic, molecular, and optical physics：Offers new experimental schemes for few-body bound states and self-bound droplets.