90 citations · 259 across the 27 of their papers we have counts for
12 papers · 1 filter
Loss-aware state space geometry for quantum variational algorithms
Ankit Gill, Kunal Pal
The natural gradient descent optimisation technique is an efficient optimising protocol for broad classes of classical and quantum systems that takes the underlying geometry of the…
A phase space approach to the wavefunction spreading and operator growth in the Krylov basis
Kunal Pal, Kuntal Pal, Keun-Young Kim
In the Wigner-Weyl phase space formulation of quantum mechanics, we analyse the problem of the spreading of an initial state or an initial operator under time evolution when descri…
Generalised state space geometry in Hermitian and non-Hermitian quantum systems
Kunal Pal
One of the key features of information geometry in the classical setting is the existence of a metric structure and a family of connections on the space of probability distribution…
Geometry of quantum states in random matrix ensembles and the chaos-integrability transition
Ankit Gill, Keun-Young Kim, Kunal Pal +1
We consider the geometry of quantum states associated with random matrix Hamiltonians belonging to ensembles that exhibit an integrable-to-chaotic transition in terms of the neares…
Statistics and Complexity of Wavefunction Spreading in Quantum Dynamical Systems
Yichao Fu, Keun-Young Kim, Kunal Pal +1
We consider the statistics of the results of a measurement of the spreading operator in the Krylov basis generated by the Hamiltonian of a quantum system starting from a specified…
Time-dependent Hamiltonians and Geometry of Operators Generated by Them
Kunal Pal, Kuntal Pal
We obtain the complexity geometry associated with the Hamiltonian of a quantum mechanical system, specifically in cases where the Hamiltonian is explicitly time-dependent. Using Ni…
Complexity in two-point measurement schemes
Ankit Gill, Kunal Pal, Kuntal Pal +1
We show that the characteristic function of the probability distribution associated with the change of an observable in a two-point measurement protocol with a perturbation can be…
Spread complexity evolution in quenched interacting quantum systems
Mamta Gautam, Kunal Pal, Kuntal Pal +3
We analyse time evolution of spread complexity (SC) in an isolated interacting quantum many-body system when it is subjected to a sudden quench. The differences in characteristics…
Time evolution of spread complexity and statistics of work done in quantum quenches
Kuntal Pal, Kunal Pal, Ankit Gill +1
We relate the probability distribution of the work done on a statistical system under a sudden quench to the Lanczos coefficients corresponding to evolution under the post-quench H…
Evolution of circuit complexity in a harmonic chain under multiple quenches
Kuntal Pal, Kunal Pal, Ankit Gill +1
We study Nielsen's circuit complexity in a periodic harmonic oscillator chain, under single and multiple quenches. In a multiple quench scenario, it is shown that the complexity sh…
Complexity in the Lipkin-Meshkov-Glick Model
Kunal Pal, Kuntal Pal, Tapobrata Sarkar
We study complexity in a spin system with infinite range interaction, via the paradigmatic Lipkin-Meshkov-Glick model, in the thermodynamic limit. Exact expressions for the Nielsen…
Nielsen complexity of coherent spin state operators
Kunal Pal, Kuntal Pal, Tapobrata Sarkar
We calculate Nielsen's circuit complexity of coherent spin state operators. An expression for the complexity is obtained by using the small angle approximation of the Euler angle p…