Matter–wave interference of particles selected from a molecular library with masses exceeding 10 000 amu

Abstract

The quantum superposition principle, a key distinction between quantum physics and classical mechanics, is often perceived as a philosophical challenge to our concepts of reality, locality or space-time since it contrasts with our intuitive expectations with experimental observations on isolated quantum systems. While we are used to associating the notion of localization with massive bodies, quantum physics teaches us that every individual object is associated with a wave function that may eventually delocalize by far more than the body's own extension. Numerous experiments have verified this concept at the microscopic scale but intuition wavers when it comes to delocalization experiments with complex objects. While quantum science is the uncontested ideal of a physical theory, one may ask if the superposition principle can persist on all complexity scales. This motivates matter-wave diffraction and interference studies with large compounds in a three-grating interferometer configuration which also necessitates the preparation of high-mass nanoparticle beams at low velocities. Here we demonstrate how synthetic chemistry allows us to prepare libraries of fluorous porphyrins which can be tailored to exhibit high mass, good thermal stability and relatively low polarizability, which allows us to form slow thermal beams of these high-mass compounds, which can be detected using electron ionization mass spectrometry. We present successful superposition experiments with selected species from these molecular libraries in a quantum interferometer, which utilizes the diffraction of matter-waves at an optical phase grating. We observe high-contrast quantum fringe patterns of molecules exceeding a mass of 10,000 amu and having 810 atoms in a single particle.

Quantum‐Assisted Metrology of Neutral Vitamins in the Gas Phase

“…Recently, it has been used to reveal the wave nature of molecules as large as 10 000 amu 15. Herein, we used this method to study the electronic properties of neutral vitamins in the gas phase.…”

Displacemon Electromechanics: How to Detect Quantum Interference in a Nanomechanical Resonator

“…Scanning the phase of the third Ramsey sequence is analogous to scanning the position of the third grating in a molecular interferometer [2], and the signature of interference is a sinusoidal dependence on ϕ. In fact, Eq.…”

“…However, the full position distribution is a result of all four components of the superposition state, whereas conventional interferometers usually combine only two optical paths. In matter-wave experiments, a successful current technique is Talbot-Lau interferometry [2], where a sequence of gratings is used to generate and observe near-field diffraction patterns. In our scheme, the quarter period of mechanical free evolution between the gratings is equivalent to far-field diffraction, so the key physics is quite different.…”

“…Our approach here focuses on generating effective mechanical diffraction gratings to measure quantum interference fringes in a mechanical object greater than 10 6 amu. The largest scale at which such fringes were observed is currently set by molecule interferometry experiments [2], and this proposal enables the mass scale of objects exhibiting quantum interference fringes to be extended by nearly 3 orders of magnitude.…”

“…The strongest tests of superposition come from matter-wave interferometry between trajectories of large molecules. Remarkably, interference can be measured using molecules of mass exceeding 10 4 atomic mass units (amu) [1,2]. The ability to create unambiguous superpositions on a mesoscopic scale would allow tests of quantum collapse theories and gravitational decoherence [3][4][5][6][7], ultimately addressing experimentally the question of why we fail to see superpositions in everyday life [8].…”