Publications
Preprints

Christian B. Mendl, Silvia Palpacelli,
Alex Kamenev,
Sauro Succi
Quantum lattice Boltzmann study of randommass Dirac fermions in one dimension
(arXiv:1706.05138)

Edwin W. Huang, Christian B. Mendl,
Shenxiu Liu,
Steve Johnston,
HongChen Jiang,
Brian Moritz,
Thomas P. Devereaux
Numerical evidence of fluctuating stripes in the normal state of highTc cuprate superconductors
(arXiv:1612.05211)
Together with Edwin, I implemented the "Determinant quantum Monte Carlo" code (C with Intel MKL) used for the computations in the paper.
Peer reviewed papers
2017

Annabelle Bohrdt, Christian B. Mendl,
Manuel Endres,
Michael Knap
Scrambling and thermalization in a diffusive quantum manybody system
[pdf]
New J. Phys. 19, 063001 (2017) [doi],
(arXiv:1612.02434)
I implemented and ran the numerical simulations in the paper, based on matrix product operators (MPOs).
The source code is available at GitHub.

Christian B. Mendl, Herbert Spohn
Shocks, rarefaction waves, and current fluctuations for anharmonic chains
[pdf]
J. Stat. Phys. 166, 841875 (2017) [doi],
(arXiv:1607.05205)
Detailed derivations related to the publication
"Searching for the TracyWidom distribution in nonequilibrium processes" below.
2016

Christian B. Mendl, Jianfeng Lu, Jani Lukkarinen
Thermalization of oscillator chains with onsite anharmonicity and comparison with kinetic theory
[pdf]
Phys. Rev. E 94, 062104 (2016) [doi],
(arXiv:1608.08308)
Using Wigner functions derived from kinetic theory to study thermalization. Motivated by the active research field "thermalization of isolated quantum systems".

Christian B. Mendl, Herbert Spohn
Searching for the TracyWidom distribution in nonequilibrium processes
[pdf]
Phys. Rev. E 93, 060101(R) (2016) [doi],
(arXiv:1512.06292)
The height fluctuations for onedimensional growth models in the KardarParisiZhang universality class are governed by the random matrix
TracyWidom distribution. Here we demonstrate that the TracyWidom distribution also occurs for the Leroux stochastic lattice gas and
hardpoint particle chains with alternating masses, when starting from domain wall initial conditions.
The result is expected to be general, and should also hold for other anharmonic chains and onedimensional quantum fluids.

Christian B. Mendl
Efficient algorithm for manyelectron angular momentum and spin diagonalization on atomic subshells
[pdf]
Commun. Comput. Phys. 19, 192204 (2016) [doi],
(arXiv:1409.6860)
A Mathematica implementation of the algorithm described in the paper is available at
GitHub.
The algorithm is an improved version of the LS diagonalization step used in the paper "Efficient algorithm for asymptoticsbased
configurationinteraction methods and electronic structure of transition metal atoms" below.
2015

Christian B. Mendl, Herbert Spohn
Low temperature dynamics of the onedimensional discrete nonlinear Schrödinger equation
[pdf]
J. Stat. Mech. (2015) P08028 [doi],
(arXiv:1505.04218)
Nonlinear fluctuating hydrodynamics applied to the discrete nonlinear Schrödinger equation.
At low temperatures, the "superfluid velocity" is almost conserved, which opens a "second sound" transportation channel.

Francesc Malet,
André Mirtschink, Christian B. Mendl, Johannes Bjerlin, Elife Ö. Karabulut,
Stephanie M. Reimann,
Paola GoriGiorgi
Density functional theory for stronglycorrelated bosonic and fermionic ultracold dipolar and ionic gases
[pdf]
Phys. Rev. Lett. 115, 033006 (2015) [doi],
(arXiv:1502.01469)
An alternative functional for DFT calculations enables simulations of ultracold gases with longranged interactions.
Also refer to the paper "Wigner localization in quantum dots from KohnSham density functional theory without symmetry breaking" below.

Jianfeng Lu, Christian B. Mendl
Numerical scheme for a spatially inhomogeneous matrixvalued quantum Boltzmann equation
[pdf]
J. Comput. Phys. 291, 303316 (2015) [doi],
(arXiv:1408.1782)
Development and implementation of an efficient algorithm for the spatially inhomogeneous matrixvalued quantum Boltzmann equation
derived from the Hubbard model. Also compare with the BoltzmannHubbard papers below concerned with the onedimensional case.

Christian B. Mendl, Herbert Spohn
Current fluctuations for anharmonic chains in thermal equilibrium
[pdf]
J. Stat. Mech. (2015) P03007 [doi],
(arXiv:1412.4609)
The C source code for the simulations can be found at
here,
and a Mathematica package and demonstration file for calculating the G coupling constants
here.
See also the papers "Equilibrium timecorrelation functions for onedimensional hardpoint systems" and
"Dynamic correlators of FermiPastaUlam chains and nonlinear fluctuating hydrodynamics" below.

Christian B. Mendl
Matrixvalued quantum lattice Boltzmann method
[pdf]
Int. J. Mod. Phys. C 26, 1550113 (2015) [doi],
(arXiv:1309.1656)
Lattice Boltzmann method (LBM) with quantum aspects: FermiDirac equilibrium functions instead of MaxwellBoltzmann,
and matrixvalued spin density matrices as distribution functions.
See also the video in the software section.

Martin L.R. Fürst, Markus Kotulla, Christian B. Mendl, Herbert Spohn
Quantum Boltzmann equation for spindependent reactions in the kinetic regime
[pdf]
J. Phys. A 48, 095204 (2015) [doi],
(arXiv:1411.2576)
Matrixvalued multicomponent Boltzmann equation derived from a general quantum field Hamiltonian.
We illustrate the approach to equilibrium by numerical simulations in the isotropic threedimensional setting.
2014

Huajie Chen, Gero Friesecke, Christian B. Mendl
Numerical methods for a KohnSham density functional model based on optimal transport
[pdf]
J. Chem. Theory Comput. 10, 43604368 (2014) [doi],
(arXiv:1405.7026)
Finite element discretization of the optimal transport map for N = 2 electrons.

Christian B. Mendl, Herbert Spohn
Equilibrium timecorrelation functions for onedimensional hardpoint systems
[pdf]
Phys. Rev. E 90, 012147 (2014) [doi],
(arXiv:1403.0213)
Comparing molecular dynamics simulations of hardpoint chains with predictions from nonlinear fluctuating hydrodynamics.
A slightly improved version of the C source code used for the simulations can be found
here,
and a Mathematica package and demonstration file for calculating the G coupling constants
here.
See also the PRL "Dynamic correlators of FermiPastaUlam chains and nonlinear fluctuating hydrodynamics" below and
the paper by Herbert Spohn "Nonlinear fluctuating hydrodynamics for anharmonic chains", J. Stat. Phys. 154, 11911227 (2014).

Suman G. Das, Abhishek Dhar,
Keiji Saito,
Christian B. Mendl, Herbert Spohn
Numerical test of hydrodynamic fluctuation theory in the FermiPastaUlam chain
[pdf]
Phys. Rev. E 90, 012124 (2014) [doi],
(arXiv:1404.7081)

Martin L.R. Fürst, Christian B. Mendl, Herbert Spohn
Dynamics of the BoseHubbard chain for weak interactions
[pdf]
Phys. Rev. B 89, 134311 (2014) [doi],
(arXiv:1312.6737)
Matrixvalued Boltzmann equation for the BoseHubbard chain in the kinetic regime, including a theoretical derivation and numerical simulations.
Concerning the FermiHubbard chain, see the papers below.

Christian B. Mendl, Francesc Malet, Paola GoriGiorgi
Wigner localization in quantum dots from KohnSham density functional theory without symmetry breaking
[pdf]
Phys. Rev. B 89, 125106 (2014) [doi],
(arXiv:1311.6011)
KohnSham DFT calculations with the SCE functional, implemented using C and Mathematica.
A slightly improved version of the C source code and a Mathematica demonstration file can be found at
GitHub.
2013

Christian B. Mendl, Herbert Spohn
Dynamic correlators of FermiPastaUlam chains and nonlinear fluctuating hydrodynamics
[pdf]
Phys. Rev. Lett. 111, 230601 (2013) [doi],
(arXiv:1305.1209)
For the underlying theory of nonlinear fluctuating hydrodynamics for anharmonic chains, refer to arXiv:1305.6412.
A Mathematica package and demonstration file for calculating the coupling constants can be found at
GitHub.

Gero Friesecke, Christian B. Mendl,
Brendan Pass, Codina Cotar,
Claudia Klüppelberg
Ndensity representability and the optimal transport limit of the HohenbergKohn functional
[pdf]
J. Chem. Phys. 139, 164109 (2013) [doi],
(arXiv:1304.0679)
Similar topic as in "Kantorovich dual solution for strictly correlated electrons in atoms and molecules".
I'm responsible for the calculations involving small atoms in the paper.

Martin L.R. Fürst, Christian B. Mendl, Herbert Spohn
Matrixvalued Boltzmann equation for the nonintegrable Hubbard chain
[pdf]
Phys. Rev. E 88, 012108 (2013) [doi],
(arXiv:1302.2075)
Followup paper for the nonintegrable case. I am mainly responsible for the numeric part, which requires more sophistication than the integrable case
to adopt the conservation laws in the numeric discretization.
The (slightly improved) C / Mathematica source code for the simulations can be found at GitHub.

Christian B. Mendl, Lin Lin
Kantorovich dual solution for strictly correlated electrons in atoms and molecules
[pdf]
Phys. Rev. B 87, 125106 (2013) [doi],
(arXiv:1210.7117)
We develop a nested optimization method to solve the Kantorovich dual formulation of optimal transport directly,
with applications to atoms and small molecules.

Christian B. Mendl, Steven Eliuk, Michelle Noga, and Pierre Boulanger
Comprehensive analysis of highperformance computing methods for filtered backprojection
[pdf]
ELCVIA 12(1): 116 (2013) [journal link].
Based on the Radon transform implementation in the software section, but for fanbeam geometry.
2012

Martin L.R. Fürst, Christian B. Mendl, Herbert Spohn
Matrixvalued Boltzmann equation for the Hubbard chain
[pdf]
Phys. Rev. E 86, 031122 (2012) [doi],
(arXiv:1207.6926)
The timedependent Wigner function is matrixvalued due to spin.

Christian B. Mendl
Efficient algorithm for twocenter Coulomb and exchange integrals of electronic prolate spheroidal orbitals
[pdf]
J. Comput. Phys. 231, 51575175 (2012) [doi],
(arXiv:1203.6256)
The paper presents a fast algorithm to calculate Coulomb/exchange integrals of prolate spheroidal electronic orbitals, which appear in diatomic molecules.
The Mathematica code used for the calculations in the paper is available at
GitHub.
2011

Christian B. Mendl
The FermiFab toolbox for fermionic manyparticle quantum systems
[pdf]
Comput. Phys. Commun. 182, 13271337 (2011) [doi],
(arXiv:1103.0872)
This paper descibes the FermiFab Matlab and Mathematica toolbox
(available at SourceForge),
focusing on the implementation details based on integer bitfields.
2010

Christian B. Mendl, Gero Friesecke
Efficient algorithm for asymptoticsbased configurationinteraction methods and electronic structure of transition metal atoms
[pdf]
J. Chem. Phys. 133, 184101 (2010) [doi],
(arXiv:1009.2013)
Several Mathematica notebooks used for the calculations are available here: [zip].
The FermiFab toolbox
(also see above paper) has originally been developed to perform the
symbolic and numerical calculations described in this paper.
2009

Christian B. Mendl, Michael M. Wolf
Unital quantum channels  Convex structure and revivals of Birkhoff's theorem
[pdf]
Commun. Math. Phys. 289, 10571086 (2009) [doi],
(arXiv:0806.2820)
Basically a compact version of my physics diploma thesis.
Conference proceedings

Christian B. Mendl (joint with Michael Knap, Johannes M. Oberreuter, Herbert Spohn)
Nonequilibrium dynamics of the BoseHubbard model and discrete nonlinear Schrödinger equation in one dimension
[pdf]
[link]
APS March Meeting 2017, New Orleans, USA

Christian B. Mendl (joint with Elizabeth Nowadnick, Yvonne Kung, Brian Moritz, Steven Johnston, Thomas Devereaux)
Doping dependence of ordered phases in the HubbardHolstein model
[pdf]
[link]
APS March Meeting 2016, Baltimore, USA

Tim Gollisch,
Vidhyasankar Krishnamoorthy, Christian B. Mendl
Neural encoding of saccadic stimuli in the retina
[pdf]
Tenth International Neural Coding Workshop Prague, Czech Republic (2012)

Christian B. Mendl (joint with Gero Friesecke)
Electronic structure of 3d transition metal atoms
[pdf]
Oberwolfach Reports 8 (2011), issue 2, pp. 17691843 [doi]
Mathematical Methods in Quantum Chemistry
Diploma Theses
Physics
Mathematics
PhD Statistical (Bio)Physics
I've completed my PhD at the LudwigMaximiliansUniversität München, supervised by
Prof. Dr. Tim Gollisch and
Prof. Dr. Erwin Frey.
Experimental work was performed at the
MaxPlanckInstitute of Neurobiology, München.
(The Gollisch group has moved to Göttingen in the meantime.)
Selected Talks and Notes
Matrixvalued Quantum Boltzmann Methods
[pdf] (November 2016).
Talk at the KINet Young Researchers Workshop: Stochastic and deterministic methods in kinetic theory,
Duke University, USA.
Searching for the TracyWidom Distribution in Nonequilibrium Processes
[pdf] (October 2016).
Talk at the Mathematical Physics and Probability seminar,
UC Davis, USA.
Determinant quantum Monte Carlo algorithm for simulating Hubbard models
[pdf] (July 2016).
Talk at the workshop "Mathematical and numerical analysis of electronic structure models",
Roscoff, France.
Doping dependence of ordered phases in the HubbardHolstein model
[pdf] (March 2016).
Talk at the APS March meeting 2016, Baltimore, USA.
Low temperature dynamics of the onedimensional discrete nonlinear Schrödinger equation
[pdf] (February 2016).
Talk at the workshop "New approaches to nonequilibrium and random systems", KITP, UC Santa Barbara, USA.
KohnSham density functional theory in the framework of "strictly correlated electrons"
[zip] (April 2014).
Talk at the "Workshop on Mathematical and numerical analysis of electronic structure models",
KonradZuse Institut Berlin, Germany.
Optimal transport limit of the HohenbergKohn functional: Kantorovich dual solution and reduced density models
[pdf] (June 2013).
Talk at the SIAM Conference on "Mathematical Aspects of Materials Science", Philadelphia, USA.
Efficient algorithm for twocenter Coulomb and exchange integrals of electronic prolate spheroidal orbitals
[pdf] (February 2012).
Talk given at CERMICS, Ecole des Ponts ParisTech, Paris, France.
Electronic structure of 3d transition metal atoms
[pptx] (June 2011).
Talk at the Oberwolfach Workshop "Mathematical Methods in Quantum Chemistry", Germany.
Unital quantum channels
[pdf] (December 2007).
Talk about unital quantum channels at the MPQ theory division Ringberg 2007 meeting, Germany.
Generalized functions
[pdf] (March 2006).
Justification of some special fundamental solutions to well known partial differential equations in the sense of generalized functions.