Dressed photons and quantum fields

Kauzya Okamura

Hirofumi Sakuma, Izumi Ojima, Motoichi Ohtsu

This article reviews recent progress in theoretical studies of dressed photons. For providing concrete physical images of dressed photons, several experimental studies are demonstrated. They are applications of dressed photons to novel optical functional devices, nano-fabrication technologies, energy conversion technologies, and photon breeding devices. After these experimental demonstrations, as the main part of this review, quantum-field theoretical formulation of dressed photons is attempted in use of the newly introduced Clebsch-dual variable of electromagnetic field. The reason for introducing the new formulation will be explained in the final section from the viewpoint to exhibit the contrast between free and interacting quantum fields in regard to their energy-momentum supports which are seldom touched upon (or forgotten) in the common physical discussions about quantum fields.

Hayato Saigo

Yameng Li, Kangkang Li, Shaohuan Ning +4 more

Abstract Here, a method to generate and shape the tri‐photon entanglement in the temporal domain via simplified single step of six‐wave mixing processes of hot atomic gas media is proposed. The effect of dressing fields on shaping the tri‐photon temporal waveform is discussed. Cascade double dressing fields will reduce the width of rectangular profile of tri‐photon waveform when compared to the single dressing field. Conversely, nested double dressing fields will widen the width of rectangular profile of tri‐photon waveform. The double dressing field will affect the coherence time of linear optical response. The relationship between phase matching bandwidth and electromagnetically induced transparency bandwidth will decide the shape of temporal waveform and coherence time in linear optical response. The transition of nonlinear optical response to linear optical response can be completed by regulating the dressing fields. The results of this proposed study have potential impact on long‐distance quantum communication, high‐dimensional entanglement, and photon storage.

M. Allegrini, E. Arimondo

Specific properties of quantum field theory are described by considering the combination of the system under investigation and the cloud of virtual or real particles associated with the field. Such a structure is called a “dressed system”, in contrast with the bare one in the absence of the interaction with the field. The description of the properties of such clouds in various physical situations is, today, an active research area. Here, we present the main features associated with virtual and real dressings, focusing on photon dressing. In analogy to virtual photon clouds dressing electrons in vacuum, virtual phonon clouds appear in solid-state physics. The interaction between real photons and the schematized two-level structure of an atom paves the way to flexible quantum control. Here, a unifying Floquet engineering approach is applied to describe single- and multiple-dressed atom configurations. Connections with the past and present atomic physics experiments are presented.

Glenn S. Solomon