Abstract
In this paper, we first analyze the stability of the unified approach, proposed in Zhang et al. (Phys Rev E 78:026709, 2008), for the nonlinear Schödinger equation in the semiclassical regime. The analysis shows that small semiclassical parameters deteriorate the accuracy of the unified approach, which will be also verified by numerical examples. Motivated by the time-splitting spectral method (Bao et al. in SIAM J Sci Comput 25:27–64, 2003), we generalize our previous work (Yang and Zhang in SIAM J Numer Anal 52:808–831, 2014), and propose frozen Gaussian approximation (FGA)-based artificial boundary conditions for solving one-dimensional nonlinear Schrödinger equation on unbounded domain. We split the linear part of the Schrödinger equation from the nonlinear part, and deal with the artificial boundary condition of the linear part by a simple strategy that all the Gaussian functions, whose dynamics are governed by the Hamiltonian flows, going out of the domain will be eliminated numerically. Since the nonlinear part is given by ordinary differential equations, it does not require artificial boundary conditions and can be solved directly. This strategy also works for the nonlinear Schrödinger equation with periodic lattice potential by using Bloch decomposition-based FGA. We present numerical examples to verify the performance of proposed numerical methods.
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Tsynkov, S.V.: Numerical solution of problems on unbounded domain: a review. Appl. Numer. Math. 27, 465–532 (1998)
Han, H.: The Artificial Boundary Method—Numerical Solutions of Partial Differential Equations in Unbounded Domains, Frontiers and Prospents of Contemporary Applied Mathematics. Higher Education Press, World Scientific, Singapore (2005)
Han, H., Wu, X.: Artificial Boundary Method. Springer, Berlin (2013)
Zheng, C.: Exact nonreflecting boundary conditions for one-dimensional cubic nonlinear Schröinger equations. J. Comput. Phys. 215, 552–565 (2006)
Xu, Z., Han, H.: Absorbing boundary conditions for nonlinear Schröinger equations. Phys. Rev. E 74, 037704 (2006)
Xu, Z., Han, H., Wu, X.: Adaptive absorbing boundary conditions for Schrödinger-type equations: application to nonlinear and multi-dimensional problems. J. Comput. Phys. 225, 1577–1589 (2007)
Zhang, J., Xu, Z., Wu, X.: Unified approach to split absorbing boundary conditions for nonlinear Schröinger equations. Phys. Rev. E 78, 026709 (2008)
Zhang, J., Xu, Z., Wu, X.: Unified approach to split absorbing boundary conditions for nonlinear Schröinger equations: two-dimensional case. Phys. Rev. E 79, 046711 (2009)
Antoine, X., Besse, C., Klein, P.: Absorbing boundary conditions for general nonlinear Schröinger equations. SIAM J. Sci. Comput. 33, 1008–1033 (2011)
Pang, G., Bian, L., Tang, S.: Almost exact boundary condition for one-dimensional Schrödinger equations. Phys. Rev. E 86, 066709 (2012)
Antoine, X., Arnold, A., Besse, C., Ehrhardt, M., Schädle, A.: A review of transparent and artificial boundary conditions techniques for linear and nonlinear Schrödinger equations. Commun. Comput. Phys. 4, 729–796 (2008)
Bao, W., Jin, S., Markowich, P.A.: Numerical study of time-splitting spectral discretizations of nonlinear Schrödinger equations in the semi-classical regimes. SIAM J. Sci. Comput. 25, 27–64 (2003)
Markowich, P., Pietra, P., Pohl, C.: Numerical approximation of quadratic observable of Schrödinger equation-type equations in the semiclassical limit. Numer. Math. 81, 595–630 (1999)
Markowich, P., Pietra, P., Pohl, C., Stimming, H.: A wigner-measure analysis of the Dufort–Frankel scheme for the Schrödinger equation. SIAM J. Numer. Anal. 40, 1281–1310 (2002)
Engquist, B., Runborg, O.: Computational high frequency wave propagation. Acta Numer. 12, 181–266 (2003)
Hagedorn, G.: Semiclassical quantum mechanics I: \(\hbar \rightarrow 0\) limit for coherent states. Commun. Math. Phys. 71, 77–93 (1980)
Jin, S., Markowich, P.A., Sparber, C.: Mathematical and computational methods for semiclassical Schrödinger equations. Acta Numer. 20, 211–289 (2011)
Jin, S., Wu, H., Huang, Z.: A hybrid phase-flow method for hamiltonian systems with discontinuous Hamiltonians. SIAM J. Sci. Comput. 31, 1303–1321 (2008)
Jin, S., Wu, H., Yang, X.: Gaussian beam methods for the Schrödinger equation in the semi-classical regime: Lagrangian and Eulerian formulations. Commun. Math. Sci. 6, 995–1020 (2008)
Jin, S., Wu, H., Yang, X., Huang, Z.: Bloch decomposition-based Gaussian beam method for the Schrödinger equation with periodic potentials. J. Comput. Phys. 229, 4869–4883 (2010)
Jin, S., Wu, H., Yang, X.: A numerical study of the Gaussian beam methods for one-dimensional Schrödinger–Poisson equations. J. Comput. Math. 28, 261–272 (2010)
Jin, S., Wu, H., Yang, X.: Semi-Eulerian and high order Gaussian beam methods for the Schrödinger equation in the semiclassical regime. Commun. Comput. Phys. 9, 668–687 (2011)
Leung, S., Qian, J., Burridge, R.: Eulerian Gaussian beams for high-frequency wave propagation. Geophysics 72, 61–76 (2007)
Leung, S., Qian, J.: Eulerian Gaussian beams for Schrödinger equations in the semiclassical regime. J. Comput. Phys. 228, 2951–2977 (2009)
Liu, H., Ralston, J.: Recovery of high frequency wave fields for the acoustic wave equation. Multiscale Model. Simul. 8, 428–444 (2009)
Liu, H., Ralston, J.: Recovery of high frequency wave fields from phase space based measurements. Multiscale Model. Simul. 8, 622–644 (2010)
Motamed, M., Runborg, O.: Taylor expansion and discretization errors in Gaussian beam superposition. Wave Motion 47, 421–439 (2010)
Qian, J., Ying, L.: Fast Gaussian wavepacket transforms and Gaussian beams for the Schrödinger equation. J. Comput. Phys. 229, 7848–7873 (2010)
Qian, J., Ying, L.: Fast multiscale Gaussian wavepacket transforms and multiscale Gaussian beams for the wave equation. Multiscale Model. Simul. 8, 1803–1837 (2010)
Ralston, J.: Gaussian beams and the propagation of singularities, Studies in PDEs. MAA Stud. Math. 23, 206–248 (1982)
Tanushev, N., Qian, J., Ralston, J.: Mountain waves and Gaussian beams. Multiscale Model. Simul. 6, 688–709 (2007)
Tanushev, N.: Superpositions and higher order Gaussian beams. Commun. Math. Sci. 6, 449–475 (2008)
Lu, J., Yang, X.: Frozen Gaussian approximation for high frequency wave propagation. Commun. Math. Sci. 9, 663–683 (2011)
Lu, J., Yang, X.: Convergence of frozen Gaussian approximation for high frequency wave propagation. Commun. Pure Appl. Math. 65, 759–789 (2012)
Lu, J., Yang, X.: Frozen Gaussian approximation for general linear strictly hyperbolic system: formulation and Eulerian methods. Multiscale Model. Simul. 10, 451–472 (2012)
Herman, M., Kluk, E.: A semiclassical justification for the use of non-spreading wavepackets in dynamics calculations. Chem. Phys. 91, 27–34 (1984)
Bao, W., Jin, S., Markowich, P.A.: On time-splitting spectral approximations for the Schrödinger equation in the semiclassical regime. J. Comput. Phys. 175, 487–524 (2002)
Yang, X., Zhang, J.: Computation of the Schrödinger equation in the semiclassical regime on unbounded domain. SIAM J. Numer. Anal. 52, 808–831 (2014)
Kuska, J.-P.: Absorbing boundary conditions for the Schrödinger equation on finite intervals. Phys. Rev. B 46, 5000 (1992)
Engquist, B., Majda, A.: Radiation boundary conditions for acoustic and elastic wave calculations. Commun. Pure Appl. Math. 32, 314–358 (1979)
Zhang, J., Xu, Z., Wu, X., Wang, D.: Stability analysis of local absorbing boundary conditions for general nonlinear Schrödinger equations in one and two dimensions. J. Comput. Math. 35, 1–18 (2017)
Lu, J., Yang, X.: Frozen Gaussian approximation for high frequency wave propagation. Commun. Math. Sci. 9, 663–683 (2011)
Delgodillo, R., Lu, J., Yang, X.: Frozen Gaussian approximation for high frequency wave propagation in periodic media. arXiv:1504.08051
Delgodillo, R., Lu, J., Yang, X.: Gauge-invariant frozen Gaussian approximation method for the Schrödinger equation with periodic potentials. SIAM J. Sci. Comput. 38, A2440–A2463 (2016)
Huang, Z., Jin, S., Markowich, P.A., Sparber, C.: A Bloch decomposition-based split-step pseudospectral method for quantum dynamics with periodic potentials. SIAM J. Sci. Comput. 29, 515–538 (2007)
Huang, Z., Jin, S., Markowich, P.A., Sparber, C.: Numerical simulation of the nonlinear Schrödinger equation with multi-dimensional periodic potentials. Multiscale Model. Simul. 7, 539–564 (2008)
Durán, A., Sanz-Serna, J.M.: The numerical integration of relative equilibrium solution. The nonlinear Schrödinger equation. IMA J. Numer. Anal. 20, 235–261 (2000)
Bao, W., Cai, Y.: Optimal error estimate of finite difference methods for the Gross–Pitaevskii equation with angular momentum rotation. Math. Comput. 82, 99–128 (2013)
Delfour, M., Fortin, M., Payre, G.: Finite-difference solutions of a nonlinear Schrödinger equation. J. Comput. Phys. 44, 277–288 (1981)
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Ricardo Delgadillo and Xu Yang were partially supported by the NSF Grants DMS-1418936 and DMS-1107291: NSF Research Network in Mathematical Sciences “Kinetic description of emerging challenges in multiscale problems of natural science”. Jiwei Zhang was partially supported by the National Natural Science Foundation of China under Grants 11771035, 91430216 and U1530401. We acknowledge support from the Center for Scientific Computing at the CNSI and MRL: an NSF MRSEC (DMR-1121053) and NSF CNS-0960316. Xu Yang was also partially supported by Hellman Family Foundation Faculty Fellowship, UC Santa Barbara. Part of work was done during Xu Yang’s visit to Beijing Computational Science Research Center, and he appreciates their hospitality.
Appendix: FGA-Base Strang-Splitting Method for Periodic Potentials
Appendix: FGA-Base Strang-Splitting Method for Periodic Potentials
We consider the nonlinear Schrödinger equation with a periodic potential in one-dimension,
The potential \(V_{\Gamma }(x)\) is periodic with respect to \(\Gamma =[0,2\pi )\) so that \(V(x/\varepsilon )\) is highly oscillatory for \(\varepsilon \ll 1\). Note that unlike (1.1), Eq. (5.1) has a factor of 1 / 2 infront of the Laplacian term. One can easily modify our previous algorithms to deal with such trivial scaling of the Hamiltonian. We leave the factor of 1 / 2 to be consistent with the work presented in [43] and [44]. The splitting algorithm described by Eqs. (3.18 3.19)–(3.20) will be used, with the main difference coming from \(V(x)=V_{\Gamma }(x/\varepsilon )\) is now periodic.
For certain potentials, the eigenfunctions for the Hamiltonian operator for the Linear Schrödinger are known. It is to our advantage to make use of this fact as diagonalization of the Linear Schrödinger equation can yield “exact” solutions. One example where diagonalization is possible is the case of periodic potentials (assumed to be smooth for simplicity). This is done using Bloch’s Theorem, thus we diagonalize the linear part of (5.1) using the Bloch-decomposition based FGA (see [43, 44]).
Remark 1
If we include an external potential in Eq. (5.1), It is still possible to obtain an asymptotic solution to the linear part of (5.1) using basis functions which diagonalize the periodic part of the Hamiltonian. This is done in [43, 44] where external potentials are also considered.
We now summarize the Bloch-decomposition-based FGA. The Bloch-decomposition FGA proposes to solve
where \(\psi ^{\varepsilon }\in L^{2}(\mathbb {R})\) is an asymptotic solution with \(L^{2}(\mathbb {R})\) initial condition. This is done by diagonalization of the periodic part of the Hamiltonian operator using Bloch waves. Bloch waves are the eigenfunctions \(u_{n}(\xi ,x)\) with corresponding eigenvalues \(E_{n}(\xi )\) of the (compact) operator
In the above equation, \(\xi \) takes any value in \([-\pi ,\pi )\) and \(n\in 1,2,\ldots \), with \(u_{n}(\xi ,x)\) normalized to unity with respect to x so that
We use periodic boundary conditions for Eq. (5.3) and we also extend \(u_{n}(\xi ,x)\) periodically with respect to x on \(\mathbb {R}\). Numerical implementation of Bloch eigenvalues and eigenfunctions in one dimension is referred to [44]. We summarize the Bloch-based FGA solution to Eq. (5.1) below,
where the evolution of \(({Q}_{n},P_{n},S_{n},a_{n})\) is governed by
where \(\mathcal {A}_{n}:=\langle u_{n}(x,\xi ),\partial u_{n}(x,\xi )\rangle \) and the classical Hamiltonian \(h_{n}\) is given by \(h_{n}(q,p)=E_{n}(p)\,+\,U(q)\). The initial conditions are \(Q_{n}(0,q,p)=q\), \(P_{n}(0,q,p)=p\), \(S_{n}(0,q,p)=0\), and \({a_{n}(0,q,p)=2^{1/2}}\).
Remark 2
In the case that \(U(x)\ne 0\) (or a constant), an asymptotic solution to Eq. (5.5) by diagonalization using Bloch waves is numerically a more delicate problem. This is because the eigenfunctions of (5.3) are defined up to a unit complex number so that \(\widetilde{u}_{n}(\xi ,x)=e^{\mathrm {i}\phi (\xi )}u_{n}(\xi ,x)\) also provides a set of Bloch waves. In this case, \(\mathcal {A}_{n}\) will not be well defined. In order to avoid numerical difficulties, one can use a Gauge-invariant algorithm described in [44].
Accuracy for the Bloch-Based Time-Splitting FGA Algorithm
Because of the Bloch-decomposition, we introduce extra errors in computing (5.1). Using an integrator of order p to solve the Hamiltonian equations (5.6), the total error is
where \(\prod _{n}f\) is the projection of f onto the nth band space. The last term of (5.7) is the error that is propagated by the initial decomposition of \(\psi _{0}^{\varepsilon }\) using the first N Bloch bands.
Remark 3
In general, the numerical cost of computing Bloch waves drastically increases as the dimensionality of the problem increases. Another major difficulty arising by using Bloch decomposition is due to the possibility of band crossings. This happens whenever the distance of the eigenvalue \(E_{n}(\xi )\) to any other eigenvalue \(E_{m}(\xi )\) is very small. In this case, the gradient of \(E_{n}(\xi )\) may not be well defined. Because band crossings are more prevalent in higher dimensions, our last example will be in 1-dimension.
Example 5.1
(Bloch eigenvalues and eigenfunctions) We compute the first few lowest energy eigenvalues and eigenfunctions to Eq. (5.3) for the periodic potential
extended periodically with respect to \([0,2\pi )\). Figure 3 displays the 8 lowest energy eigenvalues and Fig. 4 displays the absolute value of the first 4 lowest energy eigenfunctions. Despite the fact that the periodic extension is not analytic on 0 and \(2\pi \), this poses no problem numerically because of the rapid decay of the exponential function. Because we cannot preform the infinite summation of Eq. (5.5) numerically, our last example approximates \(\psi ^{\varepsilon }(t,x)\) by summing over the first 8 lowest energy band spaces.
Example 5.2
(Schrödinger with periodic potential) We choose the initial condition and nonlinearity as
We take the potential to be \(V_{\Gamma }(x/\varepsilon )\) where \(V_{\Gamma }(x)=\exp (-x^{2})\) is extended periodically with respect to the lattice \({\Gamma }\). We also note that the periodic extension of \(V_{\Gamma }(x)\) poses no numerical problem due to the rapid decay of the exponential function. Comparisons are shown in Fig. 5 where one can see that the Bloch-based time-splitting FGA algorithm approximates the solution with good accuracy.
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Delgadillo, R., Yang, X. & Zhang, J. Frozen Gaussian Approximation-Based Artificial Boundary Conditions for One-Dimensional Nonlinear Schrödinger Equation in the Semiclassical Regime. J Sci Comput 75, 1701–1720 (2018). https://doi.org/10.1007/s10915-017-0606-5
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DOI: https://doi.org/10.1007/s10915-017-0606-5
Keywords
- Frozen Gaussian approximation
- Absorbing boundary condition
- Nonlinear Schrödinger equation
- Semiclassical regime