PSAS'2024 - International Conference on Precision Physics of Simple Atomic Systems

Quantum Logic Spectroscopy of the Hydrogen Molecular Ion

12 Jun 2024, 15:05

25m

ETH Zurich- Hönggerberg Campus

Talk Session 6

Speaker

David Holzapfel

Description

I will present our latest results, implementing pure quantum state preparation, coherent manipulation, and non-destructive state readout of the hydrogen molecular ion $H_2^{+}$. The hydrogen molecular ion $H_2^{+}$ is the simplest stable molecule, and its structure can be calculated ab-initio to high precision. However, challenging properties such as high reactivity, low mass, and the absence of rovibrational dipole transitions have thus far strongly limited spectroscopic studies of $H_2^{+}$. We trap a single $H_2^{+}$ molecule together with a single beryllium ion using a cryogenic Paul trap apparatus, achieving trapping lifetimes of $11\mathrm{h}$ and ground-state cooling of the shared axial motion [1]. With this platform we have recently implemented Quantum Logic Spectroscopy of $H_2^{+}$. We utilize helium buffer-gas cooling to prepare the lowest rovibrational state of ortho-$H_2^{+}$ (rotation $L=1$, vibration $\nu =0$). We combine this with quantum-logic operations between the molecule and the beryllium ion for preparation of single hyperfine states and non-destructive readout, and demonstrate Rabi flopping on several hyperfine transitions. Our results pave the way to high-precision spectroscopy studies of $H_2^{+}$ which will enable tests of theory, metrology of fundamental constants, and an optical molecular clock.

[1] N. Schwegler, D. Holzapfel, M. Stadler, A. Mitjans, I. Sergachev, J. P. Home, and D. Kienzler, Phys. Rev. Lett. 131, 133003 (2023)