27 citations · 64 across the 9 of their papers we have counts for
14 papers
Long-range entangled criticality from coherent errors
Amir-Reza Negari, Subhayan Sahu, Jan Behrends +2
We find that coherent error can induce a phase transition from the clean surface code phase into an extended long-range entangled critical regime with diverging Markov length. To d…
Instability of Markov chains under infinitesimal coherent dissipation
Amir-Reza Negari, Yijian Zou, Timothy H. Hsieh
Under local Lindbladian evolution, the growth of conditional mutual information and its associated Markov length scale is not limited by Lieb-Robinson bounds, yet it has been uncle…
Nonadditivity in fermionic quantum Shannon theory
Farzin Salek, Amir-Reza Negari, Graeme Smith +2
We study collective state preparation and channel encoding in fermionic systems under parity superselection and composition governed by the canonical anticommutation relations. For…
Entanglement of purification for Werner states: canonical purification and nonadditivity
Zahra Baghali Khanian, Amir-Reza Negari
We prove that the von Neumann entanglement of purification is nonadditive. For two-qubit Werner states with singlet weight , we show that canonical purifica…
Approximation theorems for fermionic Gaussian states
Amir-Reza Negari, Farzin Salek, Zoltán Zimborás +3
A recurring principle in many-body physics is that sufficiently distributed interactions or correlations lead to an effectively mean-field description. For fermionic Gaussian state…
Rényi Entanglement of Purification Is Non-additive
Amir-Reza Negari, Zahra Baghali Khanian
Entanglement of purification is a fundamental measure of total correlations whose additivity remains unresolved. We study its additivity for classical states on two qubits at diffe…
Unlearnable phases of matter
Tarun Advaith Kumar, Yijian Zou, Amir-Reza Negari +2
We identify fundamental limitations in machine learning by demonstrating that non-trivial mixed-state phases of matter are computationally hard to learn. Focusing on unsupervised l…
Critical non-equilibrium phases from noisy topological memories
Amir-Reza Negari, Subhayan Sahu, Jan Behrends +2
We demonstrate the existence of an extended non-equilibrium critical phase, characterized by sub-exponential decay of conditional mutual information (CMI), in the surface code subj…
Symmetry enforces entanglement at high temperatures
Amir-Reza Negari, Leonardo A. Lessa, Subhayan Sahu
Many-body quantum systems with local interactions undergo ``sudden death of entanglement" at high temperatures, whereby thermal states become classical mixtures of product states.…
Extendibility of Fermionic Gaussian States
Amir-Reza Negari, Farzin Salek
We investigate -extendibility of fermionic Gaussian states, a property central to quantum correlations and approximations of separability. We show that these states are…
Spacetime Markov length: a diagnostic for fault tolerance via mixed-state phases
Amir-Reza Negari, Tyler D. Ellison, Timothy H. Hsieh
We establish a correspondence between the fault-tolerance of local stabilizer codes experiencing measurement and physical errors and the mixed-state phases of decohered resource st…
Measurement-induced phase transitions in the toric code
Amir-Reza Negari, Subhayan Sahu, Timothy H. Hsieh
We show how distinct phases of matter can be generated by performing random single-qubit measurements on a subsystem of toric code. Using a parton construction, such measurements m…
Chiral Ising Gross-Neveu criticality of a single Dirac cone: A quantum Monte Carlo study
S. Mojtaba Tabatabaei, Amir-Reza Negari, Joseph Maciejko +1
We perform large-scale quantum Monte Carlo simulations of SLAC fermions on a two-dimensional square lattice at half filling with a single Dirac cone with spinor components an…
An Amelioration for the Sign Problem: Adiabatic Quantum Monte Carlo
Mohammad-Sadegh Vaezi, Amir-Reza Negari, Amin Moharramipour +1
We introduce the adiabatic quantum Monte Carlo (AQMC) method, where we gradually crank up the interaction strength, as an amelioration of the sign problem. It is motivated by the a…