Multilayer Multiconfiguration Time-Dependent Hartree Theory

Wang, Haobin

doi:10.1021/acs.jpca.5b03256

Cited by 219 publications

(202 citation statements)

References 246 publications

Supporting

Mentioning

190

Contrasting

Order By: Relevance

“…70,132 Besides being a cost-effective alternative to MCTDH, TD-DMRG can also drive the definition of strongly-interacting degrees of freedom for ML-MCTDH. 24,25 For electronic structure theory, entanglement-based measures 86,106,[133][134][135][136] obtained from DMRG calculations have been demonstrated to be reliable metrics to detect strong-correlation between orbitals. When generalized to vibrational wavefunctions, [137][138][139] the same metrics could support the identification of strongly interacting vibrational degrees of freedom.…”

Section: Discussionmentioning

confidence: 99%

“…This unfavorable scaling can be partially overcome with multi-scale formulations of MCTDH, such as the Gaussian MCTDH (G-MCTDH) 18,19 or the multi-layer MCTDH (ML-MCTDH). [20][21][22][23][24][25] In G-MCTDH, only a subset of the nuclear degrees of freedom are treated with conventional MCTDH, while the rest is described semiclassically with Gaussian wavepackets. Conversely, in ML-MCTDH, strongly correlated vibrational degrees of freedom are first contracted together with MCTDH.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Large-Scale Quantum Dynamics with Matrix Product States

Baiardi

Reiher

2019

J. Chem. Theory Comput.

View full text Add to dashboard Cite

Dynamical electronic-and vibrational-structure theories have received a growing interest in the last years due to their ability to simulate spectra recorded with ultrafast experimental techniques. The exact time evolution of a molecular system can, in principle, be obtained from the time-dependent version of full configuration interaction.Such an approach is, however, limited to few-atom systems due to the exponential increase of its cost with the system dimension. In the present work, we overcome this unfavorable scaling by employing the time-dependent density matrix renormalization group (TD-DMRG) which parametrizes the time-dependent wavefunction as a matrix product state. The time-dependent Schrödinger equation is then integrated with a sweep-based algorithm, as in standard time-independent DMRG. Unlike other TD-DMRG approaches, the one presented here leads to a set of coupled equations that can be integrated exactly. The resulting theory enables us to study real-and imaginarytime evolutions of Hamiltonians comprising more than 20 degrees of freedom that are challenging for current state-of-the-art quantum dynamics algorithms. We apply our algorithm to the simulation of quantum dynamics of models of increasing complexity, ranging from simple excitonic Hamiltonians to more complex ab-initio vibronic ones.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Large-Scale Quantum Dynamics with Matrix Product States

Baiardi

Reiher

2019

J. Chem. Theory Comput.

View full text Add to dashboard Cite

show abstract

“…There exists a spectrum of techniques for dealing with non-Markovianity to varying degrees including master equations [19], quasiadiabatic path integrals [20,21], quantum Monte Carlo techniques [22,23], hierarchy equations of motion [24], multilayer [25] and multiconfiguration timedependent Hartree theory [26], time-dependent numerical [27] and density matrix [28] renormalization-group approaches, time-dependent variational matrix product states [29], and Dirac-Frenkel methods [30,31].…”

Section: Introductionmentioning

confidence: 99%

Coherent exciton dynamics in a dissipative environment maintained by an off-resonant vibrational mode

2016

View full text Add to dashboard Cite

The interplay between an open quantum system and its environment can lead to both coherent and incoherent behavior. We explore the extent to which strong coupling to a single bosonic mode can alter the coherence properties of a two-level system in a structured environment. This mode is treated exactly, with the rest of the environment comprising a Markovian bath of bosonic modes. The strength of the coupling between the two-level system and the single mode is varied for a variety of forms for the bath spectral density in order to assess whether the coherent dynamics of the two-level system are modified. We find a clear renormalization of the site population oscillation frequency that causes an altered interaction with the bath. This leads to enhanced or reduced coherent behavior of the two-level system, depending on the form of the spectral density function. We present an intuitive interpretation, based on an analytical model, to explain the behavior.

show abstract

“…and so on are the expansion coefficients for the first, second, third, ..., layers, respectively; |ϕ has been given various names such as the hierarchical low rank tensor format, the tree Tucker format, the tensor train format, and the sequential unfolding SVD. 90 The size of the system that the ML-MCTDH theory can treat increases with the number of layers in the expansion. In principle, such a recursive expansion can be carried out to an arbitrary number of layers.…”

Section: Regularization Of the Currentmentioning

confidence: 99%

A multilayer multiconfiguration time-dependent Hartree study of the nonequilibrium Anderson impurity model at zero temperature

Wang

Thoss

2018

Chemical Physics

Self Cite

View full text Add to dashboard Cite

Quantum transport is studied for the nonequilibrium Anderson impurity model at zero temperature employing the multilayer multiconfiguration time-dependent Hartree theory within the second quantization representation (ML-MCTDH-SQR) of Fock space. To adress both linear and nonlinear conductance in the Kondo regime, two new techniques of the ML-MCTDH-SQR simulation methodology are introduced: (i) the use of correlated initial states, which is achieved by imaginary time propagation of the overall Hamiltonian at zero voltage and (ii) the adoption of the logarithmic discretization of the electronic continuum. Employing the improved methodology, the signature of the Kondo effect is analyzed.

show abstract

Multilayer Multiconfiguration Time-Dependent Hartree Theory

Cited by 219 publications

References 246 publications

Large-Scale Quantum Dynamics with Matrix Product States

Large-Scale Quantum Dynamics with Matrix Product States

Coherent exciton dynamics in a dissipative environment maintained by an off-resonant vibrational mode

A multilayer multiconfiguration time-dependent Hartree study of the nonequilibrium Anderson impurity model at zero temperature

Contact Info

Product

Resources

About