13 citations · 48 across the 23 of their papers we have counts for
25 papers
Error-Adaptive Quasi-local Decoding of the Toric Code
Hossein Dehghani, Sarang Gopalakrishnan, Michael Gullans
Topological quantum memories need decoders that are both reliable and scalable, but these goals compete: globally informed decoders are accurate near threshold yet expensive, while…
Lieb-Schultz-Mattis Constraints for Quantum Channels: A Spacetime-Duality View
Sarang Gopalakrishnan, Yu-Jie Liu, Tsung-Cheng Lu +2
Quantum anomalies strongly constrain the possible behavior of many-body systems. A prime example is the Lieb-Schultz-Mattis (LSM) theorem, which relates UV symmetry and filling con…
Algorithmic Locality via Provable Convergence in Quantum Tensor Networks
Siddhant Midha, Yifan F. Zhang, Daniel Malz +2
Belief propagation has recently emerged as a powerful framework for evaluating tensor networks in higher dimensions, combining computational efficiency with provable analytical gua…
Simple slow operators and quantum thermalization
Tian-Hua Yang, Sarang Gopalakrishnan, Dmitry A. Abanin
We establish a rigorous relation between the thermalization of typical initial states and the dynamics of local operators. We introduce a concept of simple slow operators (SSOs), d…
Theory of Two-Qubit Spectroscopy of Quantum Many-Body Systems
Hossein Hosseinabadi, Pavel E. Dolgirev, Sarang Gopalakrishnan +3
Multi-qubit quantum sensors are rapidly emerging as platforms that extend the capabilities of conventional single-qubit sensing. In this work we show how suitable pulse sequences a…
Stability of mixed-state phases under weak decoherence
Yifan F. Zhang, Sarang Gopalakrishnan
We prove that the Gibbs states of classical, and commuting-Pauli, Hamiltonians are stable under weak local decoherence: i.e., we show that the effect of the decoherence can be loca…
Holographic duality between bulk topological order and boundary mixed-state order
Tsung-Cheng Lu, Yu-Jie Liu, Sarang Gopalakrishnan +1
We introduce a holographic framework for analyzing the steady states of repeated quantum channels with strong symmetries. Using channel-state duality, we show that the steady state…
Classically Sampling Noisy Quantum Circuits in Quasi-Polynomial Time under Approximate Markovianity
Yifan F. Zhang, Su-un Lee, Liang Jiang +1
While quantum computing can accomplish tasks that are classically intractable, the presence of noise may destroy this advantage in the absence of fault tolerance. In this work, we…
A robust phase of continuous transversal gates in quantum stabilizer codes
Eric Huang, Pierre-Gabriel Rozon, Arpit Dua +2
A quantum error correcting code protects encoded logical information against errors. Transversal gates are a naturally fault-tolerant way to manipulate logical qubits but cannot be…
Diverging conditional correlation lengths in the approach to high temperature
Jerome Lloyd, Dmitry A. Abanin, Sarang Gopalakrishnan
The Markov length was recently proposed as an information-theoretic diagnostic for quantum mixed-state phase transitions [Sang & Hsieh, Phys. Rev. Lett. 134, 070403 (2025)]. Here,…
Spacetime duality between sequential and measurement-feedback circuits
Tsung-Cheng Lu, Sarang Gopalakrishnan, Yizhi You
Two prevalent approaches for preparing long-range entangled quantum states are (i) linear-depth sequential unitary (SU) circuits, which apply local unitary gates sequentially, and…
Metrology of open quantum systems from emitted radiation
Siddhant Midha, Sarang Gopalakrishnan
We explore the task of learning about the dynamics of a Markovian open quantum system by monitoring the information it radiates into its environment. For an open system with Hilber…
Vortex Motion Induced Losses in Tantalum Resonators
Faranak Bahrami, Matthew P. Bland, Nana Shumiya +17
Tantalum (Ta) based superconducting circuits have been demonstrated to enable record qubit coherence times and quality factors, motivating a careful study of the microscopic origin…
Conditional Mutual Information and Information-Theoretic Phases of Decohered Gibbs States
Yifan Zhang, Sarang Gopalakrishnan
Classical and quantum Markov networks -- including Gibbs states of commuting local Hamiltonians -- are characterized by the vanishing of conditional mutual information (CMI) betwee…
Sharp Page transitions in generic Hamiltonian dynamics
Lauren H. Li, Stefan Kehrein, Sarang Gopalakrishnan
We consider the entanglement dynamics of a subsystem initialized in a pure state at high energy density (corresponding to negative temperature) and coupled to a cold bath. The subs…
Thermodynamic limitations on fault-tolerant quantum computing
Mykhailo Bilokur, Sarang Gopalakrishnan, Shayan Majidy
We investigate the thermodynamic limits on scaling fault-tolerant quantum computers due to heating from quantum error correction (QEC). Quantum computers require error correction,…
Stabilizing Non-Abelian Topological Order against Heralded Noise via Local Lindbladian Dynamics
Sanket Chirame, Abhinav Prem, Sarang Gopalakrishnan +1
An important open question for the current generation of highly controllable quantum devices is understanding which phases can be realized as stable steady-states under local quant…
Eliminating Surface Oxides of Superconducting Circuits with Noble Metal Encapsulation
Ray D. Chang, Nana Shumiya, Russell A. McLellan +15
The lifetime of superconducting qubits is limited by dielectric loss, and a major source of dielectric loss is the native oxide present at the surface of the superconducting metal.…
The effect of hyperuniform disorder on band gaps
Jonas F. Karcher, Sarang Gopalakrishnan, Mikael C. Rechtsman
The properties of semiconductors, insulators, and photonic crystals are defined by their electronic or photonic bands, and the gaps between them. When the material is disordered, L…
Spontaneous Strong Symmetry Breaking in Open Systems: Purification Perspective
Pablo Sala, Sarang Gopalakrishnan, Masaki Oshikawa +1
We explore the landscape of the decoherence effect in mixed-state ensembles from a purification perspective. We analyze the spontaneous strong-to-weak symmetry breaking (SSSB) in m…
Characterizing MPS and PEPS Preparable via Measurement and Feedback
Yifan Zhang, Sarang Gopalakrishnan, Georgios Styliaris
Preparing long-range entangled states poses significant challenges for near-term quantum devices. It is known that measurement and feedback (MF) can aid this task by allowing the p…
Nanoscale sensing of spatial correlations in nonequilibrium current noise
Yifan Zhang, Yifan F. Zhang, Rhine Samajdar +1
Nitrogen-vacancy centers are spatially resolved probes of current noise. So far, current noise sensing with NV centers has primarily been used as a way to probe equilibrium transpo…
Stable Symmetry-Protected Topological Phases in Systems with Heralded Noise
Sanket Chirame, Fiona J. Burnell, Sarang Gopalakrishnan +1
We present a family of local quantum channels whose steady-states exhibit stable mixed-state symmetry-protected topological (SPT) order. Motivated by recent experimental progress o…
Glassy word problems: ultraslow relaxation, Hilbert space jamming, and computational complexity
Shankar Balasubramanian, Sarang Gopalakrishnan, Alexey Khudorozhkov +1
We introduce a family of local models of dynamics based on ``word problems'' from computer science and group theory, for which we can place rigorous lower bounds on relaxation time…