Article
Physics, Multidisciplinary
Andrew Zhao, Nicholas C. Rubin, Akimasa Miyake
Summary: The proposed tomographic protocol estimates any k-body reduced density matrix of an n-mode fermionic state using a sampling method with randomized measurement settings generated by fermionic Gaussian unitaries. Numerical calculations demonstrate that the protocol offers a substantial improvement in constant overheads for k >= 2 compared to prior deterministic strategies. The method can also be adapted for particle-number symmetry with an option to reduce additional circuit depth at the cost of increased repetitions.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
D. Gonzalez-Cuadra, D. Bluvstein, M. Kalinowski, R. Kaubruegger, N. Maskara, P. Naldesi, T. Zache, A. M. Kaufman, M. D. Lukin, H. Pichler, B. Vermersch, Jun Ye, P. Zoller
Summary: This paper presents a fermionic quantum processor that can efficiently simulate many-body fermionic systems on hardware. By locally encoding fermionic models in a fermionic register and simulating them using fermionic gates, nonlocal fermionic statistics are achieved. The gate set, along with Rydberg-mediated interaction gates, allows for efficient circuit decompositions for digital and variational quantum simulation algorithms.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Physics, Multidisciplinary
Siddhartha Patra, Anirban Mukherjee, Siddhartha Lal
Summary: In this study, the researchers used the renormalization group method to investigate the many-particle entanglement of liquid states of quantum matter, including Fermi liquids (FL), 2D marginal Fermi liquids (MFL) and 1D Tomonaga-Luttinger liquids. They found a universal logarithmic violation of the area-law in the entanglement entropy of these liquids, providing important insights into the entanglement properties of interacting electron systems.
NEW JOURNAL OF PHYSICS
(2023)
Article
Physics, Particles & Fields
Kieran Finn, Sotirios Karamitsos, Apostolos Pilaftsis
Summary: The paper presents a framework- and reparametrisation-invariant formalism for quantum field theories including fermionic degrees of freedom. By constructing a field-space supermanifold and defining field-space tensors from the classical action, the long-standing issue regarding metric definition for fermionic theories is resolved. This allows for extending the VDW effective action and expressing any fermionic theory in an invariant manner.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Fluids & Plasmas
Gabriella G. Damas, Rogerio J. de Assis, Norton G. de Almeida
Summary: This paper investigates a quantum refrigerator operating with bosonic or fermionic thermal reservoirs, and demonstrates the advantages of fermionic reservoirs over bosonic ones.
Article
Physics, Multidisciplinary
David A. Mazziotti, Scott E. Smart, Alexander R. Mazziotti
Summary: Traditional molecular simulations using fermionic encoding can be bypassed for more efficient quantum computations. Expressing the two-electron reduced density matrix as a functional of the unencoded N-qubit-particle wave function without over-parametrization can help avoid optimization difficulties.
NEW JOURNAL OF PHYSICS
(2021)
Article
Optics
Ismail Yunus Akhalwaya, Yang-Hui He, Lior Horesh, Vishnu Jejjala, William Kirby, Kugendran Naidoo, Shashanka Ubaru
Summary: The boundary operator is crucial in various applications, and this paper presents a method to represent the full boundary operator on a quantum computer.
Article
Mechanics
Jasleen Kaur, Aritra Ghosh, Malay Bandyopadhyay
Summary: In this study, we propose a quantum analogue of the classical energy equipartition theorem for fermionic systems in open systems. The method considers the case where the system is connected to multiple reservoirs and expresses the mean energy in the steady state as an integral over the reservoir frequencies. This result applies to nonequilibrium steady states, even in the nonlinear regime far from equilibrium. Additionally, we analyze the impact of zero temperature behavior and low temperature corrections on the mean energy of the system.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Materials Science, Multidisciplinary
Eugenio Bianchi, Lucas Hackl, Mario Kieburg
Summary: This study discusses the average entanglement entropy of pure fermionic Gaussian states in subsystems and derives its formula and asymptotic behavior. The results show that in the thermodynamic limit, the average entanglement entropy of these pure random fermionic Gaussian states shares consistency with the average over eigenstates of random quadratic Hamiltonians.
Article
Quantum Science & Technology
Yaroslav Herasymenko, Maarten Stroeks, Jonas Helsen, Barbara Terhal
Summary: This article studies the approximation of the ground state energy of a fermionic Hamiltonian using a Gaussian state. In contrast to the dense case, it is proved that strictly q-local sparse fermionic Hamiltonians have a constant Gaussian approximation ratio. The results hold for any connectivity and interaction strengths. Furthermore, the constant Gaussian approximation ratio is extended to sparse fermionic Hamiltonians with quartic and quadratic terms, as well as to the sparse SYK model with strictly 4-local interactions.
Article
Physics, Multidisciplinary
Paul Lauria, Wei-Ting Kuo, Nigel R. Cooper, Julio T. Barreiro
Summary: We have experimentally created a spin-momentum lattice using a trapped Fermi gas. This lattice, formed by cyclically rotated atom-laser couplings between three atomic spin states, creates a triangular lattice in a synthetic spin-momentum space. By demonstrating and studying this lattice's dynamics with spin- and momentum-resolved absorption imaging, new possibilities for synthetic spin systems and engineering topological bands are opened up.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Michal Bialonczyk, Fernando Javier Gomez-Ruiz, Adolfo del Campo
Summary: An elementary algebraic approach is used to provide an exact description of integrable spin chains at finite temperature in the complete Hilbert space of the system. The focus is on spin chain models described in terms of free fermions, with comparisons to common approximations. Errors from these approximations near the critical point at low temperatures are identified. Additionally, the thermal distribution of observables in the transverse-field quantum Ising chain is characterized.
Article
Optics
L. Ferialdi, L. Diosi
Summary: Wick's theorem provides a connection between time ordered products of bosonic or fermionic fields, and their normal ordered counterparts. The general Wick's theorem is established for both bosonic and fermionic operators, with the surprising result that it is independent of the type of operator involved. By using a few examples, it is shown how the GWT can help reduce the amount of calculations required to solve demanding problems.
Article
Physics, Multidisciplinary
Hadiseh Alaeian, Berislav Buca
Summary: In this study, by utilizing modulated dynamical symmetries, the existence of multistability in the presence of quantum fluctuations is exactly proven in a driven-dissipative fermionic chain. Unlike the mean-field level, the quantum fluctuations themselves exhibit multistability.
COMMUNICATIONS PHYSICS
(2022)
Article
Chemistry, Physical
Oliver A. Bramley, Timothy J. H. Hele, Dmitrii Shalashilin
Summary: Zombie states are a formalism that describes coupled coherent fermionic states in a computationally tractable manner. This study extends the previous work on Zombie states and develops efficient algorithms for evaluating operators and addressing normalization. It also presents techniques for improving accuracy and calculating low-lying excited states.
JOURNAL OF CHEMICAL PHYSICS
(2022)