Meir, Ziv

Date:   Tuesday, November 26, 2019
Time:   11:00
Place:   ETH Zurich, Hönggerberg, HIT H 42
Host:    Jonathan Home

Quantum non-demolition state detection and spectroscopy of homonuclear molecules

Ziv Meir
University of Basel, Switzerland

Trapped atoms and ions are among the best-controlled quantum systems which find widespread applications in quantum information, sensing, and metrology. For molecules, however, a similar degree of control is currently lacking owing to their complex energy-level structure. Quantum-logic protocols [1] in which atomic ions serve as probes for molecular ions [2-5] are a promising route for achieving this level of control, especially with homonuclear molecules that decouple from black-body radiation.

In this talk, I will describe our experimental results [2] in achieving >99% fidelity in the quantum-non-demolition state-detection of the electronic, vibration, and rotation ground state of the homonuclear molecule, N₂⁺. The state-detection-signal amplitude is also used to map the line position and strength of an electronic transition in the molecule without destroying its state and with good agreement with previous studies that used conventional and destructive spectroscopic methods.

The presented state-detection scheme can be viewed as the molecular photon-free counterpart of the well-known state-dependent fluorescence in atomic systems. The new scheme for molecules will allow not just to detect but also to prepare Zeeman molecular quantum states through projective measurements. Preparation of Zeeman molecular states can be exploited further in precision spectroscopies of molecules, tests of possible variation of fundamental constants of nature and the creation of molecular qubits for quantum information and computation applications.

[1] P.O. Schmidt et al., Science 309, 749 (2005).
[2] M. Sinhal, Z. Meir, K. Najafian, G. Hegi and S. Willitsch, arXiv:1910.11600 (2019).
[3] F. Wolf et al., Nature 530, 457 (2016).
[4] C. W. Chou et al., Nature 545, 203 (2017).
[5] Z. Meir, G. Hegi, K. Najafian, M. Sinhal and S. Willitsch, Faraday Discuss. 217, 561 (2019).