We investigate the single-photon scattering properties of a driven three-level giant atom chirally coupled to two waveguides simultaneously in both the Markovian and the non-Markovian regimes.It is shown that under th...We investigate the single-photon scattering properties of a driven three-level giant atom chirally coupled to two waveguides simultaneously in both the Markovian and the non-Markovian regimes.It is shown that under the Markovian limit,the chiral photon-atom interactions enable nonreciprocal scattering in a single waveguide and targeted photon routing with a probability of 100%in two waveguides,while the presence of the driving field and the giant atom structure introduce a more tunable parameter to manipulate the single-photon scattering behaviors.We also examine how the non-reciprocity and routing capability are influenced by the imperfect chirality and the atomic dissipation.In the non-Markovian regime,we show that the scattering behaviors are more complicated.The non-Markovicity induced non-reciprocity and photon routing are demonstrated in this paper.We believe that those results have potential applications in quantum network engineering.展开更多
Giant atoms are known for the frequency-dependent spontaneous emission and associated interference effects.In this paper,we study the spontaneous emission dynamics of a two-level giant atom with dynamically modulated ...Giant atoms are known for the frequency-dependent spontaneous emission and associated interference effects.In this paper,we study the spontaneous emission dynamics of a two-level giant atom with dynamically modulated transition frequency.It is shown that the retarded feedback effect of the giant-atom system is greatly modified by a dynamical phase arising from the frequency modulation and the retardation effect itself.Interestingly,such a modification can in turn suppress the retarded feedback such that the giant atom behaves like a small one.By introducing an additional phase difference between the two atom-waveguide coupling paths,we also demonstrate the possibility of realizing chiral and tunable temporal profiles of the output fields.The results in this paper have potential applications in quantum information processing and quantum network engineering.展开更多
The effects of non-magnetic atom vacancy on structural, martensitic phase transitions and the corresponding magnetocMoric effect in MnCoGel-x alloys are investigated using x-ray diffraction and magnetic measurements. ...The effects of non-magnetic atom vacancy on structural, martensitic phase transitions and the corresponding magnetocMoric effect in MnCoGel-x alloys are investigated using x-ray diffraction and magnetic measurements. The introduction of non-magnetic atom vacancy leads to the decrease of the martensitic transition temperature and realizes a temperature window where magnetic and martensitic phase transitions can be tuned together. Moreover, the giant magnetocaloric effect accompanied with the coupled magnetic-structural transition is ob- tained. It is observed that the peak values of magnetic entropy change of MnCoGeo.97 are about -13.9, -35.1 and -47.4J.kg-1K-1 for △H = 2, 5, 7T, respectively.展开更多
A waveguide-QED with giant atoms,which is capable of accessing various limits of a small one,provides a new paradigm to study photon scatterings.Thus,how to achieve nonreciprocal photon transmissions via such a giant ...A waveguide-QED with giant atoms,which is capable of accessing various limits of a small one,provides a new paradigm to study photon scatterings.Thus,how to achieve nonreciprocal photon transmissions via such a giant atom setup is highly desirable.In this study,the nonreciprocal single-photon scattering characteristics of a double-drivenΛ-type three-level giant atom,where one of the transition couples to a 1D waveguide at two separate points,and the other is driven by two coherent driving fields,are investigated.It is found that a frequency-tunable single-photon diode with an ideal contrast ratio can be achieved by properly manipulating the local coupling phases between the giant atom and the waveguide,the accumulation phase between the two waveguide coupling points,the Rabi frequencies and phase difference of the two driven fields.Compared to the previous single driving schemes,on the one hand,the presence of the second driving field can provide more tunable parameters to manipulate the nonreciprocal single-photon scattering behavior.On the other hand,here perfect nonreciprocal transmission for photons with arbitrary frequencies is achievable by tuning the driving phases while the two driving fields keep on turning,which provides an alternative way to control the nonreciprocal single-photon scattering.Furthermore,the results reveal that both the location and width of each optimal nonreciprocal transmission window is also sensitive to the driving detuning,and a single-photon diode with wide or narrow bandwidth can be realized based on demand.These results may be beneficial for designing nonreciprocal single-photon devices based on a double-driven giant atom setup.展开更多
团簇结构可以稳定存在于原子核的内部。研究原子核的α团簇结构及其影响在核物理与天体物理中是一个十分重要的课题。在过去几十年里,原子核的团簇结构效应在重离子核反应中有了较多的研究。本文主要总结了在核反应与相对论重离子碰撞...团簇结构可以稳定存在于原子核的内部。研究原子核的α团簇结构及其影响在核物理与天体物理中是一个十分重要的课题。在过去几十年里,原子核的团簇结构效应在重离子核反应中有了较多的研究。本文主要总结了在核反应与相对论重离子碰撞中对原子核的α团簇结构效应的研究。例如,通过原子核的巨共振来研究原子核的团簇结构。通过核反应中的粒子(包括中子、质子以及光子)的发射与关联、集体流等研究原子核的团簇结构。进一步,我们把原子核的团簇效应延伸推广到相对论重离子碰撞中,比如,对集体流及其涨落、HBT(Hanbury Brown and Twiss)关联、多重性关联、双强子方位角关联、电磁场等的研究。展开更多
The nonlocal emitter-waveguide coupling,which gives birth to the so called giant atom,represents a new paradigm in the field of quantum optics and waveguide QED.We investigate the single-photon scattering in a one-dim...The nonlocal emitter-waveguide coupling,which gives birth to the so called giant atom,represents a new paradigm in the field of quantum optics and waveguide QED.We investigate the single-photon scattering in a one-dimensional waveguide on a two-level or three-level giant atom.Thanks to the natural interference induced by the back and forth photon transmitted/reflected between the atomwaveguide coupling points,the photon transmission can be dynamically controlled by the periodic phase modulation via adjusting the size of the giant atom.For the two-level giant-atom setup,we demonstrate the energy shift which is dependent on the atomic size.For the driven three-level giantatom setup,it is of great interest that,the Autler–Townes splitting is dramatically modulated by the giant atom,in which the width of the transmission valleys(reflection range)is tunable in terms of the atomic size.Our investigation will be beneficial to the photon or phonon control in quantum network based on mesoscopical or even macroscopical quantum nodes involving the giant atom.展开更多
文摘We investigate the single-photon scattering properties of a driven three-level giant atom chirally coupled to two waveguides simultaneously in both the Markovian and the non-Markovian regimes.It is shown that under the Markovian limit,the chiral photon-atom interactions enable nonreciprocal scattering in a single waveguide and targeted photon routing with a probability of 100%in two waveguides,while the presence of the driving field and the giant atom structure introduce a more tunable parameter to manipulate the single-photon scattering behaviors.We also examine how the non-reciprocity and routing capability are influenced by the imperfect chirality and the atomic dissipation.In the non-Markovian regime,we show that the scattering behaviors are more complicated.The non-Markovicity induced non-reciprocity and photon routing are demonstrated in this paper.We believe that those results have potential applications in quantum network engineering.
基金the National Natural Science Foundation of China(Grant Nos.12074030 and 12274107)the Science Foundation of the Education Department of Jilin Province(Grant No.JJKH20211279KJ).
文摘Giant atoms are known for the frequency-dependent spontaneous emission and associated interference effects.In this paper,we study the spontaneous emission dynamics of a two-level giant atom with dynamically modulated transition frequency.It is shown that the retarded feedback effect of the giant-atom system is greatly modified by a dynamical phase arising from the frequency modulation and the retardation effect itself.Interestingly,such a modification can in turn suppress the retarded feedback such that the giant atom behaves like a small one.By introducing an additional phase difference between the two atom-waveguide coupling paths,we also demonstrate the possibility of realizing chiral and tunable temporal profiles of the output fields.The results in this paper have potential applications in quantum information processing and quantum network engineering.
基金Supported by the National Natural Science Foundation of China under Grant No 11504222
文摘The effects of non-magnetic atom vacancy on structural, martensitic phase transitions and the corresponding magnetocMoric effect in MnCoGel-x alloys are investigated using x-ray diffraction and magnetic measurements. The introduction of non-magnetic atom vacancy leads to the decrease of the martensitic transition temperature and realizes a temperature window where magnetic and martensitic phase transitions can be tuned together. Moreover, the giant magnetocaloric effect accompanied with the coupled magnetic-structural transition is ob- tained. It is observed that the peak values of magnetic entropy change of MnCoGeo.97 are about -13.9, -35.1 and -47.4J.kg-1K-1 for △H = 2, 5, 7T, respectively.
基金supported by the China Postdoctoral Science Foundation (Grant No.2023M732028)the Zhejiang Province Key Laboratory of Quantum Technology and Device (Grant No.20230201)+2 种基金the Zhejiang Provincial Natural Science Foundation of China (Grant No.LY21A040003)the National Key Research and Development Program of China (Grant No.2021YFA1400602)the National Natural Science Foundation of China (Grant Nos.11864018,12164022,12174288 and 12274326)。
文摘A waveguide-QED with giant atoms,which is capable of accessing various limits of a small one,provides a new paradigm to study photon scatterings.Thus,how to achieve nonreciprocal photon transmissions via such a giant atom setup is highly desirable.In this study,the nonreciprocal single-photon scattering characteristics of a double-drivenΛ-type three-level giant atom,where one of the transition couples to a 1D waveguide at two separate points,and the other is driven by two coherent driving fields,are investigated.It is found that a frequency-tunable single-photon diode with an ideal contrast ratio can be achieved by properly manipulating the local coupling phases between the giant atom and the waveguide,the accumulation phase between the two waveguide coupling points,the Rabi frequencies and phase difference of the two driven fields.Compared to the previous single driving schemes,on the one hand,the presence of the second driving field can provide more tunable parameters to manipulate the nonreciprocal single-photon scattering behavior.On the other hand,here perfect nonreciprocal transmission for photons with arbitrary frequencies is achievable by tuning the driving phases while the two driving fields keep on turning,which provides an alternative way to control the nonreciprocal single-photon scattering.Furthermore,the results reveal that both the location and width of each optimal nonreciprocal transmission window is also sensitive to the driving detuning,and a single-photon diode with wide or narrow bandwidth can be realized based on demand.These results may be beneficial for designing nonreciprocal single-photon devices based on a double-driven giant atom setup.
文摘团簇结构可以稳定存在于原子核的内部。研究原子核的α团簇结构及其影响在核物理与天体物理中是一个十分重要的课题。在过去几十年里,原子核的团簇结构效应在重离子核反应中有了较多的研究。本文主要总结了在核反应与相对论重离子碰撞中对原子核的α团簇结构效应的研究。例如,通过原子核的巨共振来研究原子核的团簇结构。通过核反应中的粒子(包括中子、质子以及光子)的发射与关联、集体流等研究原子核的团簇结构。进一步,我们把原子核的团簇效应延伸推广到相对论重离子碰撞中,比如,对集体流及其涨落、HBT(Hanbury Brown and Twiss)关联、多重性关联、双强子方位角关联、电磁场等的研究。
文摘The nonlocal emitter-waveguide coupling,which gives birth to the so called giant atom,represents a new paradigm in the field of quantum optics and waveguide QED.We investigate the single-photon scattering in a one-dimensional waveguide on a two-level or three-level giant atom.Thanks to the natural interference induced by the back and forth photon transmitted/reflected between the atomwaveguide coupling points,the photon transmission can be dynamically controlled by the periodic phase modulation via adjusting the size of the giant atom.For the two-level giant-atom setup,we demonstrate the energy shift which is dependent on the atomic size.For the driven three-level giantatom setup,it is of great interest that,the Autler–Townes splitting is dramatically modulated by the giant atom,in which the width of the transmission valleys(reflection range)is tunable in terms of the atomic size.Our investigation will be beneficial to the photon or phonon control in quantum network based on mesoscopical or even macroscopical quantum nodes involving the giant atom.
