General Lab Information

Marton Lajer

Condensed Matter Theory, Condensed Matter Physics and Materials Science Department

Marton Lajer

Brookhaven National Laboratory

Condensed Matter Physics and Materials Science Department
Bldg. 734
P.O. Box 5000
Upton, NY 11973-5000

(631) 344-5089
mlajer@bnl.gov

I am a postoctoral fellow in the Condensed Matter Theory group. My current research interest focuses on develpoing  Hamiltonian Truncation methods to Quantum Field Theories, the extension of these methods to 2+1 dimensions and their application to effective models arising in strongly interacting condensed matter systems.

Recently I have also become interested in the possible utilization of intermediate scale quantum computers to implement Hamiltonian methods for QFTs and many-body systems.

Expertise | Education | Appointments | Publications


Expertise

Hamiltonian truncations
— Nonperturbative study of quantum field theories [and, by extension, quantum many-body systems]
— Real-time physics (time evolution after quenches)
— Spectrum, matrix elements, 0,1,2-point correlators
— Landau-Ginzburg (phi^n), sine/sinh-Gordon, Bullough-Dodd, Massive Schwinger models

Integrable Quantum Field Theories in 2 dimensions
— Thermodynamic / Asymptotic Bethe Ansatz
— Form factors and their finite volume corrections[, 2-point correlators]
— sinh-Gordon, Bullough-Dodd[, Affine Toda, sine-Gordon, etc.] models

Finite volume physics
— Exponential (Lüscher) corrections to offdiagonal matrix elements in integrable models
— Hamiltonian (Rayleigh-Schrödinger, Wigner-Brillouin) perturbation theory in finite volume for general QFT

Low dimensional/low energy effective models of QCD

Feynman diagrammatic techniques

Implementing numerical methods in Wolfram Language, C/C++, Python[, Matlab]

Education

PhD in physics, 2020, Eotvos Lorand University, Budapest, Hungary
dissertation: Finite volume methods in the quantum sinh-Gordon theory
Supervisor: Zoltan Bajnok

MSc in physics, 2016, Eotvos Lorand University
Master's thesis title: Nonperturbative study of the 1+1 dimensional $\phi^4$ model by Hilbert Space Truncation (in Hungarian)
Supervisor: Zoltan Bajnok

BSc in physics, 2013, Eotvos Lorand University
Bachelor's thesis title: Theoretical and Experimental Examination of the Optical Properties of Graphene
Thin Films (in Hungarian)
Supervisors: Jozsef Cserti, Gyongyi Pergerne Klupp, Katalin Kamaras

Professional Appointments

Postdoctoral research associate, Brookhaven National Laboratory (2022-2024)
Independent contractor academically affiliated to Brookhaven National Laboratory (2021-2022)
Junior Research Fellow, Wigner Research Centre for Physics (2020)
PhD Student, Eotvos Lorand University, Department of Theoretical Physics (2016-2020)
Junior Research Fellow (part-time), Wigner Research Centre for Physics (2016-2020)
 

Selected Publications

  • Lajer M, Konik RM, Pisarski RD, Tsvelik AM (2022) When cold, dense quarks in 1+1 and 3+1 dimensions are not a Fermi liquid. Physical Review D 105:. https://doi.org/10.1103/physrevd.105.054035
  • Konik R, Lájer M, Mussardo G (2021) Approaching the self-dual point of the sinh-Gordon model. Journal of High Energy Physics 2021:. https://doi.org/10.1007/jhep01(2021)014
  • Bajnok Z, Lájer M, Szépfalvi B, Vona I (2019) Leading exponential finite size corrections for non-diagonal form factors. Journal of High Energy Physics 2019:. https://doi.org/10.1007/jhep07(2019)173
  • Bajnok Z, Balog J, Lájer M, Wu C (2018) Field theoretical derivation of Lüscher's formula and calculation of finite volume form factors. Journal of High Energy Physics 2018:. https://doi.org/10.1007/jhep07(2018)174
  • Bajnok Z, Lajer M (2016) Truncated Hilbert space approach to the 2d ? 4 theory. Journal of High Energy Physics 2016:. https://doi.org/10.1007/jhep10(2016)050
Marton Lajer

Brookhaven National Laboratory

Condensed Matter Physics and Materials Science Department
Bldg. 734
P.O. Box 5000
Upton, NY 11973-5000

(631) 344-5089
mlajer@bnl.gov

Marton's Links