Observation of Time-Domain Rabi Oscillations in the Landau-Zener Regime with a Single Electronic Spin

Abstract

Under resonant conditions, a long sequence of landau-zener transitions can lead to Rabi oscillations. Using a nitrogen-vacancy (NV) center spin in diamond, we investigated the interference between more than 100 Landau-Zener processes. We observed the new type of Rabi oscillations of the electron spin resulting from the interference between successive Landau-Zener processes in various regimes, including both slow and fast passages. The combination of the control techniques and the favorable coherent properties of NV centers provides an excellent experimental platform to study a variety of quantum dynamical phenomena. The phenomenon of Rabi oscillations, first studied in 1937 [1], occurs in almost any quantum system under the influence of resonant external driving and is at the heart of various spectroscopic techniques. Landau-Zener (LZ) transitions, first studied in 1932 [2][3][4][5], are intriguing phenomena that are ubiquitous in quantum systems, typically occurring when two energy levels of a quantum system undergo an avoided crossing.Under suitable conditions LZ transitions can be treated as quantum coherent processes, and multiple such processes can interfere constructively or destructively [4]. Depending on the details of the interference, a long and regular sequence of LZ processes can exhibit resonance behavior similar to that seen in Rabi oscillations under weak driving conditions.The oscillations obtained in the case of constructive interference can therefore be seen as a manifestation of Rabi oscillations in the regime of ultrastrong driving [6]. Moreover, the interference between LZ processes gives rise to a number of novel features distinct from the case of weak driving. Particularly interesting is the fact that the patterns of the resonance lines vary drastically depending on whether each passage through the avoided crossing is slow or fast [6].The experimental observation of Rabi oscillations in the LZ regime requires stringent conditions. The coherence time of the quantum system is required to be long enough to allow the coherent interference between multiple LZ processes, and the control fields are required to be accurate and stable in order to precisely adjust the quantum phases that govern the interference effects. In addition, the time resolution of the measurement needs to be high enough to allow the monitoring of the dynamics on short timescales.With the recent advances in various quantum systems [7,8], a number of experiments were able to demonstrate the controlled interference of LZ transitions. Interference between two LZ transitions has been observed in gaseous molecules [9], semiconductor-based quantum dots [10], NV centers [11], and atoms in optical lattices [12]. Evidence for various interference effects involving multiple LZ transitions has been observed in the steady-state behavior of continuously driven superconducting qubits [13,14] and NV centers [15]. However, although those steady-state behaviors have been reported, the experimental observation of the abundant time-domain evolu...

Breaking the rotating wave approximation for a strongly driven dressed single-electron spin

“…Explicitly this means ∆ν(t) = ∆ν FM cos(2πν FM t + φ), where ∆ν FM is the modulation amplitude of the microwave drive, and φ is the phase of the FM modulation. This is fundamentally different to coherent spin control via interference of multiple Landau-Zener transitions, which is another technique based on frequency modulating the driving field 37 . In the experiments, we achieve FM modulation by connecting a radio frequency (RF) source to the FM input of the MW source.…”

Landau-Zener-Stückelberg-Majorana lasing in circuit quantum electrodynamics

“…8,17,[19][20][21] In particular, it was predicted that interference between multiple LZSM transitions can produce periodic oscillations of the level occupations. Quite recently these oscillations have been observed in the time domain for a spin ensemble by making use of NV centres in diamond 16 . Since they are reminiscent of Rabi oscillations, they can be termed as LZSM-Rabi-like oscillations, however, for brevity, we will call them Rabi-like oscillations.…”

Quantum systems under frequency modulation

“…By simply changing the basis through a π/2 rotation around the y-axis the frequency modulation will transform into a Rabi-type drive. Although extremely simple, this connection has only recently been studied systematically [39] and observed experimentally using a nitrogen-vacancy spin in diamond [40]. Another example is the strongly nonadiabatic regime of frequency modulation, where the Landau-Zener transition formula cannot be applied [41][42][43].…”