Rzhanov Institute Maps Electric Fields of Single Rydberg Atoms

Researchers at the Rzhanov Institute of Semiconductor Physics SB RAS, alongside collaborators from Novosibirsk State University and Saint-Petersburg State University, have achieved precise three-dimensional control over the electric field surrounding a single rubidium Rydberg atom. The work demonstrates the ability to manipulate the atom within an ultrahigh-vacuum glass cell using eight electrodes, a configuration essential for advancing quantum computing and simulation with neutral atoms. This research utilizes a technique called three-photon Stark spectroscopy. The measured three-photon spectra exhibit Stark shifts and splittings in good agreement with theoretical calculations, results also of interest for Rydberg electrometry.

Three-Photon Spectroscopy of Single Rubidium Rydberg Atoms

Eight electrodes, deposited on the inner surfaces of an ultrahigh-vacuum glass cell, were utilized to manipulate the electric environment of the lone atom, allowing for independent tuning of the field along all three spatial directions. This level of control is crucial because Rydberg states, atoms with an electron excited to a very high energy level, are exceptionally sensitive to external electric fields. Researchers at the Rzhanov Institute of Semiconductor Physics SB RAS, alongside collaborators from Novosibirsk State University and Saint-Petersburg State University, employed a spectroscopic study that simultaneously reveals both the electric field-induced shifts and splittings of the Rydberg resonances, simplifying the calibration process.

This advancement builds upon existing methods for creating large-scale arrays of ultracold neutral atoms, a promising platform for quantum computing and simulation, where Rydberg excitation, energizing an atom’s electron to a higher orbital, is crucial for generating entanglement. The ability to independently tune the electric field along all three spatial axes, and to compensate for stray fields, is demonstrated through observation of Stark shifts and splittings in the three-photon resonance spectra, aligning with theoretical predictions. This level of control isn’t solely about achieving precise quantum operations; the work also holds implications for Rydberg electrometry, an application utilizing highly sensitive Rydberg atoms as electric field sensors.

This level of control is vital for advancing quantum computing and simulation platforms reliant on Rydberg atom arrays, where even minor electric field fluctuations can disrupt delicate quantum states. The technique used allows for spectroscopic study of the electric fields surrounding the atom. The experiment involved trapping a single rubidium atom within an optical dipole trap while simultaneously applying and observing the electric field generated by the eight electrodes.

The ability to precisely study electric fields around individual atoms has moved closer to reality, potentially unlocking advancements in quantum computing and highly sensitive electrometry. This was achieved within an ultrahigh-vacuum glass cell utilizing eight electrodes to manipulate the atom’s environment. The work builds upon years of research into alkali-metal Rydberg states, extending previous spectroscopic studies to the realm of ultracold, trapped atoms and paving the way for more complex quantum systems.

The pursuit of stable quantum systems often conjures images of elaborate, cryogenically cooled setups; however, recent work demonstrates remarkable control can be achieved with surprisingly simple architecture. This level of precision isn’t merely about isolating an atom, but about establishing a pathway toward highly localized quantum systems where individual atomic states can be manipulated with unprecedented accuracy. The work also holds promise for Rydberg electrometry, an application where the extreme sensitivity of Rydberg atoms to electric fields can be harnessed for precision sensing.

A single rubidium atom, held in isolation, is revealing new insights into the fundamental forces governing interactions between Rydberg atoms. This level of precision stems from a spectroscopic technique: three-photon Stark spectroscopy.

Stark Spectroscopy Techniques: Historical Methods

The current state of Stark spectroscopy reveals a field deeply rooted in techniques refined over decades, now converging on increasingly precise control of individual atoms. Early investigations into alkali-metal Rydberg states, beginning with gas discharge lamps and dye lasers in the 1970s, yielded the first measurements of scalar polarizabilities. These initial measurements progressed to two-photon Doppler-free spectroscopy within vapor cells, and later, sophisticated beam experiments utilizing selective field ionization for Rydberg atom detection, as demonstrated by Zimmerman and colleagues in a classical work. Researchers subsequently adapted these methods for use with ultracold atoms, leveraging laser cooling and trapping to achieve unprecedented levels of control. The development of magneto-optical traps facilitated the study of Stark component splitting in rubidium 41D states, while trap-loss spectroscopy offered a simpler, albeit slower, method for observing Stark shifts.

This work builds on the established sensitivity of Rydberg states to external electric fields, a property increasingly leveraged for applications like Rydberg electrometry. The team’s innovation centers on a three-photon excitation scheme, allowing for simultaneous observation of both Stark shifts and resonance splitting within a single rubidium atom held in an ultrahigh-vacuum glass cell. These shifts are absent in the three-photon excitation scheme used in this experiment. This level of control isn’t merely a calibration exercise; the ability to tune the electric field with single-atom resolution opens pathways toward highly localized quantum systems and advanced sensing capabilities, and these results are also of interest for Rydberg electrometry.