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Publications

Preprints

Preprints 2024

• Runtime Reduction in Linear Quantum Charge-Coupled Devices using the Parity Flow Formalism
  F. Dominguez, M. Fellner, B. Klaver, St. Rombouts, Ch. Ertler, W. Lechner
  arXiv:2410.16382 [ pdf ]

• SWAP-less Implementation of Quantum Algorithms
  B. Klaver, St. Rombouts, M. Fellner, A. Messinger, K. Ender, K. Ludwig, W. Lechner
  arXiv:2408.10907 [ pdf ]

• Quantum optimization with globally driven neutral atom arrays
  M. Lanthaler, K. Ender, C. Dlaska, W. Lechner
  arXiv:2410.03902 [ pdf ]

• Performance of Parity QAOA for the Signed Max-Cut Problem
  A. Weidinger, G. Mbeng, M. Fellner, D. Khachatryan, W. Lechner
  arXiv:2409.14786 [ pdf ]

• Fault-tolerant quantum computing with the parity code and noise-biased qubits
  A. Messinger, V. Torggler, B. Klaver, M. Fellner, W. Lechner
  arXiv:2404.11332 [ pdf ]

• On the uniqueness of compiling graphs under the parity transformation
  F. Dreier, W. Lechner
  arXiv:2401.11980 [ pdf ]

Preprints 2023

• Flexible constraint compilation in the parity architecture
  R. ter Hoeven, A. Messinger, W. Lechner
  arXiv:2304.12879 [ pdf ]

Preprints 2022

• Rotated ansatz for approximate counterdiabatic driving
  G. Mbeng, W. Lechner
  arXiv:2207.03553 [ pdf ]

• Low-depth Circuit Implementation of Partiy Constraints for Quantum Optimization
  J. Unger, A. Messinger, B. Niehoff, M. Fellner, W. Lechner
  arXiv:2211.11287 [ pdf ]

  
  

Publications

Publications 2024

• Scalable Parity Architecture With a Shuttling-Based Spin Qubit Processor
  F. Ginzel, M. Fellner, Ch. Ertler, Lars R. Schreiber, H. Bluhm, W. Lechner
  Phys. Rev. B 110, 075302 (2024).

• The quantum Ising chain for beginners
  G. Mbeng, A. Russomanno, G. Santoro
  SciPost Phys. Lect. Notes 82 (2024).

• Comparing planar quantum computing platforms at the quantum speed limit
  D. Basilewitsch, C. Dlaska, W. Lechner
  Phys. Rev. Research 6, 020326 (2024).

 Publications 2023

• Error mitigation for quantum approximate optimization
  A. Weidinger, G. Mbeng, W. Lechner
  Phys. Rev. A 108, 032408 (2023).

• Constant Depth Code Deformations in the Parity Architecture
  A. Messinger, M. Fellner, W. Lechner
  2023 IEEE International Conference on Quantum Computing and Engineering (2023).

• Encoding-Independent Optimization Problem Formulation for Quantum Computing
  F. Dominguez, J. Unger, M. Traube, B. Mant, Ch. Ertler, W. Lechner
  Front. Quantum. Sci. Technol. 2 (2023).

• Rydberg blockade based parity quantum optimization
  M. Lanthaler, C. Dlaska, K. Ender, W. Lechner
  Phys. Rev. Lett. 130, 220601 (2023).

• Scalable set of reversible parity gates for integer factorization
  M. Lanthaler, B. Niehoff, W. Lechner
  Communications Physics 6, 73 (2023).

• Scalable quantum processors empowered by the Fermi scattering of Rydberg electrons
  M. Khazali, W. Lechner
  Communications Physics 6, 57 (2023).

• Parity Quantum Optimization: Compiler
  K. Ender, R. ter Hoeven, B. Niehoff, M. Drieb-Schön, W. Lechner
  Quantum 7, 950 (2023).

• Parity Quantum Optimization: Encoding Contraints
  M. Drieb-Schön, K. Ender, Y. Javanmard, W. Lechner
  Quantum 7, 951 (2023).
  
  
• Parity Quantum Optimization: Benchmarks
  M. Fellner, K. Ender, R. ter Hoeven, W. Lechner
  Quantum 7, 952 (2023).
  

 Publications 2022 

• Universal Parity Quantum Computing
  M. Fellner, A. Messinger, K. Ender, W. Lechner
  Phys. Rev. Lett. 129, 180503 (2022).

• Two-Dimensional Z 2 Lattice Gauge Theory on a Near-Term Quantum Simulator: Variational Quantum Optimization, Confinement and Topological Order
  L. Lumia, P. Torta, G. Mbeng, G. Santoro, E. Ercolessi, M. Burello, M. Wauters
  PRX Quantum 3, 020320 (2022).
  
  
• Avoiding barren plateaus via transferability of smooth solutions in a Hamiltonian variational ansatz
  A. Mele, G. Mbeng, G. Santoro, M. Collura, P. Torta
  Phys. Rev. A 106, L060401 (2022).
  

• Symmetric projected entangled-pair states analysis of a phase transition in coupled spin-1/2 ladders
  J. Hasik, G. Mbeng, S. Capponi, F. Becca, A. Läuchli
  Phys. Rev. B 106, 125154 (2022).
  
  
• Applications of universal parity quantum computation
  M. Fellner, A. Messinger, K. Ender, W. Lechner
  Phys. Rev. A 106, 042442 (2022).
  
  
• CircuitQ: An open-source toolbox for superconducting circuits
  P. Aumann, T. Menke, W. Oliver, W. Lechner
  New J. Physics 24, 093012 (2022).
  
  
• Modular Parity Quantum Approximate Optimization
  K. Ender, A. Messinger, M. Fellner, C. Dlaska, W. Lechner
  PRX Quantum 3, 030304 (2022).
  
  
• Demonstration and modelling of time-bin entangled photons from a quantum dot in a nanowire                                              P. Aumann, M. Prilmüller, F. Kappe, L. Ostermann, D. Dalacu, P. J. Poole, H. Ritsch, W. Lechner, G. Weihs
  AIP Advances 12, 055115 (2022).
  
  
• Polynomial scaling enhancement in ground-state preparation of Ising spin models via counter-diabatic driving
  A. Hartmann, G. Mbeng, W. Lechner
  Phys. Rev. A 105, 022614 (2022).
  
  
• Quantum optimization via four-body Rydberg gate
  C. Dlaska, K. Ender, G. Mbeng, A. Kruckenhauser, W. Lechner, R. van Bijnen
  Phys. Rev. Lett. 128, 120503 (2022).

Publications 2021

• The information complexity of learning tasks, their structure and their distance                                                                              A. Achille, G. Paolini, G. Mbeng, S. Soatto
  Information and Inference: A Journal of the IMA 10/1, 51-72 (2021).
  
  
• Embedding Overhead Scaling of Optimization Problems in Quantum Annealing
  M. Könz, W. Lechner, G. Katzgraber, M. Troyer
  PRX Quantum 2, 040322 (2021).
  
  
• Minimal Constraints in the Parity Formulation of Optimization Problems
  M. Lanthaler, W. Lechner
  New J. Phys. 23, 083039 (2021).
  
  
• Two-parameter counter-diabatic driving in quantum annealing
  L. Prielinger, A. Hartmann, Y. Yamashiro, K. Nishimura, W. Lechner, H. Nishimori
  Phys. Rev. Research 3, 013227 (2021).

Publications 2020

• Multi-spin counter-diabatic driving in many-body quantum Otto refrigerators
  A. Hartmann, V. Mukherjee, G.B. Mbeng, W. Niedenzu, W. Lechner
  Quantum 4, (2020).

• Quantum Approximate Optimization with Parallelizable Gates
  W. Lechner
  IEEE Transactions on Quantum Engineering 1, 31002206 (2020).

• Encrypt me! A game-based approach to Bell inequalities and quantum cryptography
  A. Lopez-Incera, A. Hartmann, W. Dür
  Eur. J. Phys. 41, 065702 (2020).

• Many-body quantum heat engines with shortcuts to adiabaticity
  A. Hartmann, V., Mukherjee, W. Niedenzu, W. Lechner
  Phys. Rev. Research 2, 023145 (2020).

• Quantum Expectation-Maximization Algorithm
  H. Miyahara, K. Aihara, W. Lechner
  Phys. Rev. A 101, 012326 (2020). 

• Perspectives of quantum annealing: Methods and implementations
  P. Hauke, H. G. Katzgraber, W. Lechner, H. Nishimori, W. D. Oliver
  Rep. Prog. Phys. 83, 054401 (2020).  

Publications 2019

• Quantum phase transition with inhomogeneous driving in the Lechner-Hauke-Zoller model
  A. Hartmann, W. Lechner
  Phys. Rev. A 100, 032110 (2019).

• Rapid counter-diabatic sweeps in lattice gauge adiabatic quantum computing
  A. Hartmann, W. Lechner
  New J. Phys. 21, 043025 (2019).

• A Quantum N-Queens Solver
  V. Torggler, P. Aumann, H. Ritsch, W. Lechner
  Quantum 3, 149 (2019).

• Designing ground states of Hopfield networks for quantum state preparation
  C. Dlaska, L. M. Sieberer, W. Lechner
  Phys. Rev. A 99, 032342 (2019).

Publications 2018

• Programmable superpositions of Ising configurations
  L. M. Sieberer, W. Lechner
  Phys. Rev. A 97, 052329 (2018).
  

Publications 2017

• A Coherent Quantum Annealer with Rydberg Atoms
  A. Glaetzle, R. van Bijnen , P. Zoller and W. Lechner
  Nature Communications 8, 15813 (2017).
  
  
• Glass Transitions in Monodisperse Cluster-Forming Ensembles Vortex Matter in Type-1.5 Superconductors
  R. Diaz-Mendez, F. Mezzacapo, W. Lechner, F. Cinti, E. Babaev, G. Pupillo
  Phys. Rev. Lett. 118, 067001 (2017).

Publications 2016

• A Transmon Quantum Annealer Decomposing Many-Body Ising Constraints Into Pair Interactions
  M. Leib, P. Zoller and W. Lechner
  Quantum Science and Technology 1, 015008 (2016).
  

Publications 2015

• A Quantum Annealing Architecture with All-to-All Connectivity from Local Interactions
  W. Lechner, P. Hauke, and P. Zoller,
  Science Advances 1, 1500838 (2015).

• From classical to quantum non-equilibrium dynamics of Rydberg excitations in optical lattices
  M. Mattioli, A. Glätzle, and W. Lechner,
  New J. Phys. 17, 113039 (2015).

• Tunable defect interactions in classical and quantum solids
  W. Lechner, F. Cinti, G. Pupillo,
  Phys. Rev. A 92, 053625 (2015).

• Monodisperse cluster crystals Classical and quantum dynamics
  R. Diaz-Mendez, F. Mezzacapo, F. Cinti, W. Lechner, G. Pupillo
  Phys. Rev. E 92, 052307 (2015).

• Spatial Patterns of Rydberg Excitations from Logarithmic Pair Interactions
  W. Lechner and P. Zoller,
  Phys. Rev. Lett. 115, 125301 (2015).

• Probing Entanglement in Adiabatic Quantum Optimization with Trapped Ions
  P. Hauke, L. Bonnes, M. Heyl, and W. Lechner,
  Frontiers in Physics 3, 21 (2015).

• A string reaction coordinate for the folding of a polymer chain
  C. Leitold, W. Lechner, and C. Dellago
  J. Phys. Condens. Matter 27, 194126 (2015). 

• Cluster Luttinger liquids and emergent supersymmetric conformal critical points in the one-dimensional soft-shoulder Hubbard model
  M. Dalmonte, W. Lechner, Zi Cai, M. Mattioli, A. M. Läuchli, G. Pupillo
  Phys. Rev. B 92, 045106 (2015). 

• Entropy and Kinetics of Point-Defects in Two-Dimensional Dipolar Crystals
  W. Lechner, D. Polster, G. Maret, C. Dellago, and P. Keim
  Phys. Rev. E 91, 032304 (2015).

Publications 2014

• The Role of Quantum Fluctuations in the Hexatic Phase of Cold Polar Molecules
  W. Lechner, H.-P. Büchler, and P. Zoller,
  Phys. Rev. Lett. 112, 255301 (2014). 

• Defect-induced supersolidity with soft-core Bosons
  F. Cinti, T. Macri, W. Lechner, G. Pupillo, T. Pohl,
  Nature Comm. 5 , 3235 (2014).

• Equilibrium and non-equilibrium cluster phases in colloids with competing interactions
  E. Mani, W. Lechner, W. Kegel, P. Bolhuis,
  Soft Matter 10, 4479 (2014).

Publications 2013

• Self-organized defect strings in two-dimensional crystals
  W. Lechner, D. Polster, G. Maret, P. Keim, C. Dellago,
  Phys. Rev. E 88, 060402 (2013).

• From Classical to Quantum Glasses with Ultracold Polar Molecules
  W. Lechner and P. Zoller,
  Phys. Rev. Lett. 111, 185306 (2013).

• Cluster Luttinger liquids of Rydberg-dressed atoms in optical lattices
  M. Mattioli, M. Dalmonte, W. Lechner, and G. Pupillo,
  Phys. Rev. Lett. 111, 165302 (2013).

• Resonances in dissipative optomechanics with nanoparticles Sorting, speed rectification, and transverse cooling
  S. J. M. Habraken, W. Lechner, and P Zoller,
  Phys. Rev. A 97, 053808 (2013).

• Cavity Optomechanics of Levitated Nano-Dumbbells Non-Equilibrium Phases and Self-Assembly
  W. Lechner, S. J. M. Habraken, N. Kiesel, M. Aspelmeyer, P. Zoller,
  Phys. Rev. Lett. 110, 143604 (2013).

Publications 2011 - 2006

• Reaction coordinates for the crystal nucleation of colloidal suspensions extracted from the reweighted path ensemble
  W. Lechner, C. Dellago, and P. G. Bolhuis,
  J. Chem. Phys. 135, 154110 (2011). 

• On the Relation Between Projections of the Reweighted Path Ensemble
  P. G. Bolhuis and W. Lechner,
  J. Stat. Phys. 145, 841 (2011).

• Role of the prestructured surface cloud in crystal nucleation
  W. Lechner, C. Dellago, and P. G. Bolhuis,
  Phys. Rev. Lett. 106, 085701 (2011). 

• Non-linear reaction coordinate analysis in the reweighted path ensemble
  W. Lechner, J. Rogal, J. Juraszek, B. Ensing and P. G. Bolhuis,
  J. Chem. Phys. 133, 174110 (2010).

• The reweighted path ensemble
  J. Rogal, W. Lechner , J. Juraszek, B. Ensing and P. G. Bolhuis,
  J. Chem. Phys. 133, 174109 (2010).

• Defect interactions in two-dimensional colloidal crystals vacancy and interstitial strings
  W. Lechner and C. Dellago,
  Soft Matter 5, 2752 - 2758 (2009).

• Point defects in two-dimensional colloidal crystals simulation vs. elasticity theory
  W. Lechner and C. Dellago,
  Soft Matter 5, 646 (2009).

• Accurate determination of crystal structures based on averaged local bond order parameters
  W. Lechner and C. Dellago,
  J. Chem. Phys. 129, 114707 (2008).

• Displacement fields of point defects in two-dimensional colloidal crystals
  W. Lechner, E. Schöll-Paschinger, and C. Dellago,
  J. Phys. Condens. Matter 20, 404202 (2008).

• On the efficiency of path sampling methods for the calculation of free energies from non-equilibrium simulations
  W. Lechner and C. Dellago,
  J. Stat. Mech. P04001 (2007).
  
  
• Equilibrium free energies from fast-switching trajectories with large time steps
  W. Lechner, H. Oberhofer, C. Dellago and P. Geissler,
  J. Chem. Phys. 124, 044113 (2006).