Effects of Nearly Degenerate States on Photon-Echo Behavior

Lambert, L.; Compaan, A.; Abella, I. D.

doi:10.1103/physreva.4.2022

Cited by 56 publications

(7 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…p&3 is given by exchanging the subscripts 12 and 13 in Eq. (3). The response for a homogeneously broadened system can be straightforwardly obtained by inserting these results in (2) and calculating the intensity, yielding an expression in agreement with previous publications [13,16].…”

Section: Effects Of Correlation Between Inhomogeneously Broadened Trasupporting

confidence: 75%

“…[1]. Early observations in atomic and molecular systems include resonance fluorescence [2] and photon-echo experiments [3,4]. These optical experiments were preceded by the observation of quantum beats (QB) in nuclear quadrupole resonance [5], which are theoretically very similar, although not so experimentally.…”

Section: Effects Of Correlation Between Inhomogeneously Broadened Tramentioning

confidence: 99%

“…The only step which is performed numerically is of correlation suppress the beats, but they are also suppressed in the case in which the inhomogeneous widths of the upper levels are not identical to each other, even if they are perfectly correlated. While some of the first optical observations of quantum beats were in an inhomogeneously broadened medium, due to either random crystal fields [3] or Doppler broadening [4], the question of correlation was generally not thought to be important, as perfect correlation corresponding to a fixed shift is expected in either case. The theoretical treatment of the earlier spin-echo quantum beats did include the possibility of noncorrelation, although it was included in the simplest possible way, by simply integrating over a distribution of energy-level differences between the levels [5].…”

Section: Effects Of Correlation Between Inhomogeneously Broadened Tramentioning

confidence: 99%

See 2 more Smart Citations

Effects of correlation between inhomogeneously broadened transitions on quantum beats in transient four-wave mixing

Cundiff

1994

Phys. Rev. A

View full text Add to dashboard Cite

The transient four-wave-mixing signal from a three-level system is calculated in the short-pulse limit including a general distribution function for the energies of the levels between which beating occurs. This allows an examination of the effects of correlation between the energetic splitting of the levels. As expected, the results demonstrate that the degree of correlation can significantly alter the four-wavemixing signal. However, the results also show that in the case where the level energies are completely correlated, in a rigorous sense, but that the correlation is not a simple offset, a strong modification of the beat amplitude occurs. This case describes the type of correlation expected in semiconductor quantum wells. Examination of several representative cases demonstrates that these effects can easily be incorrectly ascribed to dephasing. PACS number(s): 42.50.Md, 78.66.w Quantum beats arise due to the excitation of a quantum-mechanical coherent superposition of several discrete levels. Their presence has been observed in many optical experiments and they are considered a spectroscopic tool for the determination of energy splittings [1]. Early observations in atomic and molecular systems include resonance fluorescence [2] and photon-echo experiments [3,4]. These optical experiments were preceded by the observation of quantum beats (QB) in nuclear quadrupole resonance [5], which are theoretically very similar, although not so experimentally. With the recent advances in short-pulse laser technology, which have made subpicosecond pulses readily available, nonlinear optical techniques have been extensively applied to the study of electronic excitations in semiconductors and semiconductor heterostructures [6]. The picosecond time scale for dephasing in these materials necessitates the use of such short-pulse widths. The experiments that have been performed include the observations of QB between excitons confined to distinct regions in a quantum well [7,8], heavy-and light-hole excitons [9], free and bound excitons [10], Zeeman split excitons [ll], and excitons and biexcitons [12]. Related experiments include the observation of coherent oscillations between coupled quantum wells [13], a distinction between true QB and interference between the radiated field from two distinct transitions [known as polarization interference (PI)] [14], and interference between the different excitonic states [15].Inhomogeneous broadening is we11 known to strongly influence the effects of nonlinear optical experiments, and in the case of transient four-wave mixing (TFWM) is responsible for the free decay observed for a homogeneously broadened two-level system becoming a photon echo.The theoretical treatment presented in most of the recent work on quantum beats has largely ignored the presence of inhomogeneous broadening [13,16,17], although it was included in the case in which the beats were thought to arise from PI [7,16]. These treatments are generally p(3) b) k2 ! ! ! ! Time Time FIG. 1. (a) The origin of the four terms which...

show abstract

Section: Effects Of Correlation Between Inhomogeneously Broadened Trasupporting

confidence: 75%

Section: Effects Of Correlation Between Inhomogeneously Broadened Tramentioning

confidence: 99%

Section: Effects Of Correlation Between Inhomogeneously Broadened Tramentioning

confidence: 99%

See 1 more Smart Citation

Effects of correlation between inhomogeneously broadened transitions on quantum beats in transient four-wave mixing

Cundiff

1994

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…1e ) can cause quantum beats-like signal, the so-called polarization interference (PI), arising from electromagnetic interference at the detector 4 . Because PI has the same temporal shape as the quantum beats, many researchers have devoted much effort to distinguish these phenomena since the first discovery by Lambert et al 52 . There exist somewhat complicated methods for the distinction of quantum beats form PI, which are based on time-resolved or spectrally resolved analyses in the three-pulse four-wave-mixing experiments 45 , 53 .…”

Section: Resultsmentioning

confidence: 99%

Ultrafast quantum beats of anisotropic excitons in atomically thin ReS2

et al. 2018

View full text Add to dashboard Cite

Quantum beats, periodic oscillations arising from coherent superposition states, have enabled exploration of novel coherent phenomena. Originating from strong Coulomb interactions and reduced dielectric screening, two-dimensional transition metal dichalcogenides exhibit strongly bound excitons either in a single structure or hetero-counterpart; however, quantum coherence between excitons is barely known to date. Here we observe exciton quantum beats in atomically thin ReS2 and further modulate the intensity of the quantum beats signal. Surprisingly, linearly polarized excitons behave like a coherently coupled three-level system exhibiting quantum beats, even though they exhibit anisotropic exciton orientations and optical selection rules. Theoretical studies are also provided to clarify that the observed quantum beats originate from pure quantum coherence, not from classical interference. Furthermore, we modulate on/off quantum beats only by laser polarization. This work provides an ideal laboratory toward polarization-controlled exciton quantum beats in two-dimensional materials.

show abstract

“…Since each molecule in the mixture irradiates an electromagnetic field, the sum of these fields consists of a coherent sum of the induced polarizations of all the components. This opens the possibility to observe beats between modes in the different molecules, ,, which are sometimes called polarization beats . Figure a shows the calculated time-resolved CARS signal for a mixture of 80% benzene and 20% toluene.…”

Section: Resultsmentioning

confidence: 99%

Femtosecond Time-Resolved CARS Spectroscopy on Binary Gas-Phase Mixtures: A Theoretical and Experimental Study of the Benzene/Toluene System

et al. 1998

View full text Add to dashboard Cite

Femtosecond time-resolved CARS measurements on benzene, toluene, and binary mixtures of these molecules have been performed in the gas phase. Whereas a two-pulse excitation process prepares benzene in a single vibrational state, a vibrational wave packet is excited in toluene, which gives rise to oscillatory patterns in the CARS signal. For the mixed system one finds beats between modes coherently excited in both molecules. The results are analyzed using perturbative quantum calculations. It is shown that the rotational degree of freedom is responsible for the decay of the CARS signal in all cases. Furthermore, it is demonstrated that the details of the excitation process have to be incorporated in the calculation to obtain the correct amplitudes of the oscillating signals.

show abstract

Effects of Nearly Degenerate States on Photon-Echo Behavior

Abstract: A density-matrix analysis is given of some properties of photon echoes arising from nearly

Cited by 56 publications

References 15 publications

Effects of correlation between inhomogeneously broadened transitions on quantum beats in transient four-wave mixing

Effects of correlation between inhomogeneously broadened transitions on quantum beats in transient four-wave mixing

Ultrafast quantum beats of anisotropic excitons in atomically thin ReS2

Femtosecond Time-Resolved CARS Spectroscopy on Binary Gas-Phase Mixtures: A Theoretical and Experimental Study of the Benzene/Toluene System

Contact Info

Product

Resources

About