The hierarchy problem asks why the mass of the Higgs particle is so much lighter than the Planck-scale mass. Considering the interaction of the Higgs particle and an elementary particle in the Planck-scale, to cope with that big difference, the conventional calculation needs the help of an arbitrary, excessive fine-tuning, that is, the huge cancellation between the bare mass term and the quantum correction, without obeying a physical principle such as symmetry. Thus, it is often said to be unnatural. On the other hand, the theory of supersymmetry (SUSY) is a strong candidate naturally to solve the hierarchy problem. However, any sign of SUSY even for the quantum mechanics (QM) version had not been firmly, directly observed in the physical reality until Cai et al. reported the observation of N=2 SUSY and its spontaneous breaking in a trapped ion quantum simulator for the prototype model for SUSY QM. In this discussion, I derive a no-go theorem for the spontaneous SUSY breaking in the strong coupling limit for the quantum Rabi model with the A^2-term, and at the same time, I show another limit proposed in the scheme by Cai et al. can avoid the no-go theorem and take that model from the N=2 SUSY to its spontaneous breaking. I propose a theoretical method to observe how the effect of A^2-term appears in the spontaneous SUSY breaking.
Within the framework of exact quantum electrodynamics in dispersing and absorbing media, we have studied the emission from an initially in the upper state prepared emitter in a high quality cavity in the case, when there are two cavity modes that resonantly interact with the emitter. In particular, when one of the modes is in resonance with the emitter transition and the other mode is tuned to the frequency equal to the Rabi splitting of the first mode, the effect of Rabi resonance is observed.
The experimental advance on light-matter interaction into strong couplings has invalidated Jaynes-Cummings model and brought quantum Rabi model (QRM) to more relevance. The QRM only involves linear coupling via a single-photon process (SPP), while nonlinear two-photon process (TPP) is weaker and conventionally neglected. However, we find a contrary trend that enhancing the linear coupling might not suppress more the nonlinear effect but backfire to trigger some collapse of linear characters. Indeed, in strong SPP couplings a tiny strength of TPP may dramatically change properties of the system…
Acoustic spontaneous emission into bulk dielectrics can be a strong source of decoherence in quantum devices, especially when a qubit is in the presence of piezoelectric materials. We study the dynamics of a qubit coupled to an acoustic resonator by a piezoelectric film. By varying the surface topography of the resonator from rough to polished to shaped, we explore the crossover from fast decay of an excited qubit to quantum-coherent coupling between the qubit and an isolated phonon mode. Our experimental approach may be used for precision measurements of crystalline vibrations, the design of …
Supersymmetry (SUSY) helps solve the hierarchy problem in high-energy physics and provides a natural groundwork for unifying gravity with other fundamental interactions. While being one of the most promising frameworks for theories beyond the Standard Model, its direct experimental evidence in nature still remains to be discovered. Here we report experimental realization of a supersymmetric quantum mechanics (SUSY QM) model, a reduction of the SUSY quantum field theory for studying its fundamental properties, using a trapped ion quantum simulator. We demonstrate the energy degeneracy caused by…
We have numerically obtained theoretical results for the collapse and the revival of the quantum Rabi oscillations for low average number of coherent photons injected on a two-level system in a lossy resonant cavity. We have adopted the multimode Jaynes-Cummings model for the same and especially treated the ``Ohmic" loss to the walls of the cavity, the leakage from the cavity, and the loss due to the spontaneous emission through the open surface of the cavity. We have compared our results with the experimental data obtained by Brune et al [Phys. Rev. Lett. 76, 1800 (1996)] in this regard.
An open quantum system operated at the spectral singularities where dimensionality reduces, known as exceptional points (EPs), demonstrates distinguishing behavior from the Hermitian counterpart. Here, we present an analytical description of local density of states (LDOS) for microcavity featuring chiral EPs, and unveil the anomalous spontaneous emission dynamics from a quantum emitter (QE) due to the non-Lorentzian response of EPs. Specifically, we reveal that a square Lorentzian term of LDOS contributed by chiral EPs can destructively interfere with the linear Lorentzian profile, resulting i…
We explore an extended quantum Rabi model describing the interaction between a two-mode bosonic field and a three-level atom. Quantum phase transitions of this few degree of freedom model is found when the ratio $η$ of the atom energy scale to the bosonic field frequency approaches infinity. An analytical solution is provided when the two lowest-energy levels are degenerate. According to it, we recognize that the phase diagram of the model consists of three regions: one normal phase and two superradiant phases. The quantum phase transitions between the normal phase and the two superradiant pha…
Spontaneous Emission in the presence of Quantum Mirrors
Wyant College of Optical Sciences and Department of Physics, University of Arizona（亚利桑那大学怀雅特光学科学学院和物理系）；Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción（康塞普西翁大学理学院物理数学系物理系）
