294 citations · 1.2k across the 35 of their papers we have counts for
35 papers
Microscopically exact transport equation for the quantum Calogero model
Vir B. Bulchandani, Fabian H. L. Essler
We derive an exact transport equation for the quantum Calogero model, i.e. inverse-square interacting bosons on a line, from microscopic first principles.
Scalable tests of quantum contextuality from stabilizer-testing nonlocal games
Wanbing Zhao, H. W. Shawn Liew, Wen Wei Ho +2
Soon after the dawn of quantum error correction, DiVincenzo and Peres observed that stabilizer codewords could give rise to simple proofs of quantumness via contextuality. This dis…
Asymmetric decay of quantum many-body scars in XYZ quantum spin chains
Dhiman Bhowmick, Vir B. Bulchandani, Wen Wei Ho
Quantum many-body scars are atypical energy eigenstates of chaotic quantum many-body systems that prevent certain special non-equilibrium initial conditions from thermalizing. We p…
A theory of quasiballistic spin transport
Jeffrey Z. Song, Hyunsoo Ha, Wen Wei Ho +1
A recent work [Mierzejewski et al., Phys. Rev. B 107, 045134 (2023)] observed "quasiballistic spin transport" - long-lived and transiently ballistic modes of the magnetization dens…
Orbital Wigner functions and quantum transport in multiband systems
Johannes Mitscherling, Dan S. Borgnia, SuryaNeil Ahuja +2
Traditional theories of electron transport in crystals are based on the Boltzmann equation and do not capture physics arising from quantum coherence. We introduce a transport forma…
Duality between string and computational order in symmetry-enriched topological phases
Paul Herringer, Vir B. Bulchandani, Younes Javanmard +2
We present the first examples of topological phases of matter with uniform power for measurement-based quantum computation. This is possible thanks to a new framework for analyzing…
Hydrodynamics of spin transport in the Haldane-Shastry chain
Vir B. Bulchandani, Hyunsoo Ha
We use kinetic theory and the thermodynamic Bethe ansatz to derive the hydrodynamics of spin transport in the Haldane-Shastry chain. We obtain analytical expressions for relaxation…
Nash states versus eigenstates for many-body quantum systems
Chuqiao Lin, Vir B. Bulchandani, Shivaji L. Sondhi
Eigenstates of observables such as the Hamiltonian play a central role in quantum mechanics. Inspired by the pure Nash equilibria that arise in classical game theory, we propose ''…
The classical limit of Quantum Max-Cut
Vir B. Bulchandani, Stephen Piddock
It is well-known in physics that the limit of large quantum spin should be understood as a semiclassical limit. This raises the question of whether such emergent classicality f…
Random-matrix models of monitored quantum circuits
Vir B. Bulchandani, S. L. Sondhi, J. T. Chalker
We study the competition between Haar-random unitary dynamics and measurements for unstructured systems of qubits. For projective measurements, we derive various properties of the…
Revised Enskog equation for hard rods
Vir B. Bulchandani
We point out that Percus's collision integral for one-dimensional hard rods [J. K. Percus, Physics of Fluids 12, 1560-1563 (1969)] does not preserve the thermal equilibrium state i…
Nonlinear breathers with crystalline symmetries
Frank Schindler, Vir B. Bulchandani, Wladimir A. Benalcazar
Nonlinear lattice models can support "discrete breather" excitations that stay localized in space for all time. By contrast, the localized Wannier states of linear lattice models a…
Quantum tasks assisted by quantum noise
Chuqiao Lin, Vir B. Bulchandani, Shivaji L. Sondhi
We introduce a notion of expected utility for quantum tasks and discuss some general conditions under which this is increased by the presence of quantum noise in the underlying res…
Unusual ergodic and chaotic properties of trapped hard rods
Debarshee Bagchi, Jitendra Kethepalli, Vir B. Bulchandani +4
We investigate ergodicity, chaos and thermalization for a one-dimensional classical gas of hard rods confined to an external quadratic or quartic trap, which breaks microscopic int…
Dynamics and transport in the boundary-driven dissipative Klein-Gordon chain
Abhinav Prem, Vir B. Bulchandani, S. L. Sondhi
Motivated by experiments on chains of superconducting qubits, we consider the dynamics of a classical Klein-Gordon chain coupled to coherent driving and subject to dissipation sole…
Hot band sound
Vir B. Bulchandani, David A. Huse
Chaotic lattice models at high temperature are generically expected to exhibit diffusive transport of all local conserved charges. Such diffusive transport is usually associated wi…
Playing nonlocal games with phases of quantum matter
Vir B. Bulchandani, Fiona J. Burnell, S. L. Sondhi
The parity game is an example of a nonlocal game: by sharing a Greenberger-Horne-Zeilinger (GHZ) state before playing this game, the players can win with a higher probability than…
A multi-player, multi-team nonlocal game for the toric code
Vir B. Bulchandani, Fiona J. Burnell, S. L. Sondhi
Nonlocal games yield an unusual perspective on entangled quantum states. The defining property of such games is that a set of players in joint possession of an entangled state can…
Onset of many-body quantum chaos due to breaking integrability
Vir B. Bulchandani, David A. Huse, Sarang Gopalakrishnan
Integrable quantum systems of finite size are generically robust against weak enough integrability-breaking perturbations, but become quantum chaotic and thermalizing if the integr…
Quasiparticle kinetic theory for Calogero models
Vir B. Bulchandani, Manas Kulkarni, Joel E. Moore +1
We show that the quasiparticle kinetic theory for quantum and classical Calogero models reduces to the free-streaming Boltzmann equation. We reconcile this simple emergent behaviou…
How smooth is quantum complexity?
Vir B. Bulchandani, S. L. Sondhi
The "quantum complexity" of a unitary operator measures the difficulty of its construction from a set of elementary quantum gates. While the notion of quantum complexity was first…
Hydrodynamics of quantum spin liquids
Vir B. Bulchandani, Benjamin Hsu, Christopher P. Herzog +1
Quantum spin liquids are topological states of matter that arise in frustrated quantum magnets at low temperatures. At low energies, such states exhibit emergent gauge fields and f…
Recursive contact tracing in Reed-Frost epidemic models
Saumya Shivam, Vir B. Bulchandani, S. L. Sondhi
We introduce a Reed-Frost epidemic model with recursive contact tracing and asymptomatic transmission. This generalizes the branching-process model introduced by the authors in a p…
Superdiffusion in spin chains
Vir B. Bulchandani, Sarang Gopalakrishnan, Enej Ilievski
This review summarizes recent advances in our understanding of anomalous transport in spin chains, viewed through the lens of integrability. Numerical advances, based on tensor-net…