Floquet control of the gain and loss in a PT-symmetric optical coupler

Wu, Yi; Zhu, Bo; Hu, Shufang; Zhou, Zheng; Zhong, Honghua

doi:10.1007/s11467-016-0642-x

Cited by 24 publications

(9 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…time-independent) potentials has been prolific. Recently, manipulation of the spontaneous PT -symmetry breaking (and non-Hermitian physics) by making use of periodic driving schemes has also attracted much attention [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. For example, as shown in references [10,20], the spontaneoussymmetry-breaking phase transition emerges even for arbitrarily weak gain-loss coefficient by adjusting the parameters of periodic driving field.…”

Section: Introductionmentioning

confidence: 99%

Spin Josephson effects of spin–orbit-coupled Bose–Einstein condensates in a non-Hermitian double well

Tang¹,

Zhou²,

Zeng³

et al. 2022

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

In this paper, we investigate the spin and tunneling dynamics of a spin-orbit-coupled noninteracting Bose-Einstein condensate in a periodically driven non-Hermitian double-well potential. Under high-frequency driving, we obtain the effective time-averaged Hamiltonian by using the standard time-averaging method, and analytically calculate the Floquet quasienergies, revealing that the parity-time (PT)-breaking phase transition appears even for arbitrarily small non-Hermitian parameters when the spin-orbit coupling strength takes half-integer value, irrespective of the values of other parameters used. When the system is PT-symmetric with balanced gain and loss, we find numerically and analytically that in the broken PT-symmetric regions, there will exist the net spin current together with a vanishing atomic current, if we drop the contribution of the exponential growth of the norm to the current behaviors. When the system is non-PT-symmetric, though the quasienergies are partial complex, a stable net spin current can be generated by controlling the periodic driving field, which is accompanied by a spatial localization of the condensate in the well with gain. The results deepen the understanding of non-Hermitian physics and could be useful for engineering a variety of devices for spintronics.

show abstract

Section: Introductionmentioning

confidence: 99%

Spin Josephson effects of spin–orbit-coupled Bose–Einstein condensates in a non-Hermitian double well

Tang¹,

Zhou²,

Zeng³

et al. 2022

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

show abstract

“…time-independent) potentials. Recently, however, a parallel activity associated with time-dependent PT -symmetric systems has started to attract increasing attention [29][30][31][32][33][34][35][36][37][38][39]. The excitement for this line of research stems from two reasons: the first one is fundamental and it is associated with the expectation that new pathways in the PT -arena can lead to new exciting phenomena.…”

mentioning

confidence: 99%

Experimental Realization of Floquet PT -Symmetric Systems

2017

View full text Add to dashboard Cite

We provide an experimental framework where periodically driven PT -symmetric systems can be investigated. The set-up, consisting of two UHF oscillators coupled by a time-dependent capacitance, demonstrates a cascade of PT -symmetric broken domains bounded by exceptional point degeneracies. These domains are analyzed and understood using an equivalent Floquet frequency lattice with local PT -symmetry. Management of these PT -phase transition domains is achieved through the amplitude and frequency of the drive.PACS numbers: 42.25.Bs, 11.30.Er Introduction -Non-Hermitian Hamiltonians H which commute with the joint parity-time (PT ) symmetry might have real spectrum when some parameter γ, that controls the degree of non-hermiticity, is below a critical value γ PT [1]. In this parameter domain, termed exact PT -phase the eigenfunctions of H are also eigenfunctions of the PT -symmetric operator. In the opposite limit, coined the broken PT -phase, the spectrum consists (partially or completely) of pairs of complex conjugate eigenvalues while the eigenfunctions cease to be eigenfunctions of the PT operator. The transition point γ = γ PT shows all the characteristic features of an exceptional point (EP) singularity where both eigenfunctions and eigenvalues coalesce.Although originally the interest on PT -symmetric systems was driven by a mathematical curiosity [1], during the last five years the field has blossomed and many applications in areas of physics, ranging from optics [2-18], matter waves [19,20] and magnonics [21,22] [4, 9, 10, 12-14, 17, 18, 24-26]. Importantly, the existence of the PT phase transition and specifically of the EP singularity played a prominent role in many of these studies, and subsequent technological applications.Though the exploitation of PT -symmetric systems has been prolific, most of the attention has been devoted to static (i.e. time-independent) potentials. Recently, however, a parallel activity associated with time-dependent PT -symmetric systems has started to attract increasing attention [29][30][31][32][33][34][35][36][37][38][39]. The excitement for this line of research stems from two reasons: the first one is fundamental and it is associated with the expectation that new pathways in the PT -arena can lead to new exciting phenomena. This expectation is further supported by the fact that the investigation of time-dependent Hermitian counterparts led to a plethora of novel phenomena-examples include Rabi oscillations [40], Autler-Townes splitting [41], dynamical localization [42], dynamical Anderson localization [43], and coherent destruction of tunneling [44,45] (for a review see [46]). The second reason is technological and it is associated with the possibility to use driving schemes as a flexible experimental knob to realize new forms of reconfigurable synthetic matter [47,48]. Specif-

show abstract

“…The characteristics of the timeperiodic-driven two-level system with 𝒫𝒯 symmetry were studied and the corresponding phase diagram as a function of the perturbation strength and frequency was obtained. [24][25][26][27][28][29] The time evolution of the two-level system with a timedependent non-Hermitian Hamiltonian without 𝒫𝒯 symmetry was investigated and showed that the system was in general unstable with exponential growth or decay. [30] Recently, the analytical results for the parity-time-symmetric two-level system under synchronous combined modulations was studied.…”

Section: Introductionmentioning

confidence: 99%

Analytic solutions for generalized PT -symmetric Rabi models*

et al. 2019

View full text Add to dashboard Cite

We theoretically investigate the exact solutions for generalized parity–time( P T )-reversal-symmetric Rabi models driven by external fields with monochromatic periodic, linear, and parabolic forms, respectively. The corresponding exact solutions are presented in terms of the confluent Heun equations without any approximation. In principle, the analytic solutions derived here are valid in the whole parameter space. Such a kind of study may offer potential coherent control schemes of the P T -symmetric two-level systems.

show abstract

Floquet control of the gain and loss in a PT-symmetric optical coupler

Cited by 24 publications

References 42 publications

Spin Josephson effects of spin–orbit-coupled Bose–Einstein condensates in a non-Hermitian double well

Spin Josephson effects of spin–orbit-coupled Bose–Einstein condensates in a non-Hermitian double well

Experimental Realization of Floquet PT -Symmetric Systems

Analytic solutions for generalized PT -symmetric Rabi models*

Contact Info

Product

Resources

About