Speaker
Description
Modeling nonequilibrium few-body dynamics beyond static ground states presents a fundamental challenge for classical computing due to exponential Hilbert space scaling and real-time sign problems. As a hallmark of universal few-body physics, the Efimov effect dictates that three identical bosons at the unitarity limit ($a \to \infty$) form an infinite geometric cascade of bound trimers. While static properties of Efimov states have been extensively mapped, observing the real-time adiabatic formation of an Efimov trimer as it emerges from the continuum remains a major challenge in ultracold atom experiments. Sweeping two-body interactions $a(t)$ toward resonance triggers severe inelastic three-body recombination losses ($K_3 \propto a^4$), destroying the atomic sample before adiabatic state preparation can complete, while spatial confinement sweeps introduce symmetry breaking and inter-channel coupling. To bypass these limitations, we present a digital quantum simulation framework that probes the real-time formation of Efimov states by dynamically sweeping an effective spatial dimension $D = D(t)$ at unitarity. At $a = \infty$, angular degrees of freedom decouple, reducing the three-body problem to an effective one dimensional hyperradial Schrödinger equation where $D(t)$ acts as a dynamic centrifugal control parameter. We map the hyperradius onto a compact qubit register (with $6\text{–}8$ qubits) and execute an adiabatic ramp starting from a diffuse halo state near the critical dimension ($D \approx 2.35$) up to the three-dimensional Efimov regime ($D = 3.0$). Because evolution on a quantum computer is strictly unitary, this approach entirely eliminates particle loss. Moreover, sweeping toward $D=3.0$ leads to a monotonically opening energy gap, which naturally protects the wavepacket against non-adiabatic excitations into the continuum. We present proof-of-concept numerical results showing state fidelity exceeding $99\%$ with low Trotter gate depths. This work establishes a decay-free protocol for observing nonequilibrium threshold phenomena on current quantum hardware, opening oportunities for scalable multi-channel $N \ge 4$ simulations that quickly exceed classical reach.