165 citations · 670 across the 24 of their papers we have counts for
24 papers · 1 filter
Computational Work Extraction: The Complexity of Catalysts
Atul Singh Arora, Shantanav Chakraborty, Alexandru Cojocaru +2
We prove maximal separations: -qubit systems can have ergotropy, while every efficient process extracts negligible work, even for Hamiltonians consisting of single-qubit…
Randomized Quantum Singular Value Transformation
Xinzhao Wang, Yuxin Zhang, Soumyabrata Hazra +3
We introduce the first randomized algorithms for Quantum Singular Value Transformation (QSVT), a unifying framework for many quantum algorithms. Standard implementations of QSVT re…
Fast computational deep thermalization
Shantanav Chakraborty, Soonwon Choi, Soumik Ghosh +1
Deep thermalization refers to the emergence of Haar-like randomness from quantum systems upon partial measurements. As a generalization of quantum thermalization, it is often assoc…
Simulating quantum collision models with Hamiltonian simulations using early fault-tolerant quantum computers
Kushagra Garg, Zeeshan Ahmed, Subhadip Mitra +1
We develop randomized quantum algorithms to simulate quantum collision models, also known as repeated interaction schemes, which provide a rich framework to model various open-syst…
Quantum singular value transformation without block encodings: Near-optimal complexity with minimal ancilla
Shantanav Chakraborty, Soumyabrata Hazra, Tongyang Li +3
We develop new algorithms for Quantum Singular Value Transformation (QSVT), a unifying framework that encapsulates most known quantum algorithms and serves as the foundation for ne…
Sample Complexity of Black Box Work Extraction
Shantanav Chakraborty, Siddhartha Das, Arnab Ghorui +2
Extracting work from a physical system is one of the cornerstones of quantum thermodynamics. The extractable work, as quantified by ergotropy, necessitates a complete description o…
Unstructured Adiabatic Quantum Optimization: Optimality with Limitations
Arthur Braida, Shantanav Chakraborty, Alapan Chaudhuri +4
In the circuit model of quantum computing, amplitude amplification techniques can be used to find solutions to NP-hard problems defined on -bits in time …
Implementing any Linear Combination of Unitaries on Intermediate-term Quantum Computers
Shantanav Chakraborty
We develop three new methods to implement any Linear Combination of Unitaries (LCU), a powerful quantum algorithmic tool with diverse applications. While the standard LCU procedure…
Quantum Regularized Least Squares
Shantanav Chakraborty, Aditya Morolia, Anurudh Peduri
Linear regression is a widely used technique to fit linear models and finds widespread applications across different areas such as machine learning and statistics. In most real-wor…
Limit theorems and localization of three state quantum walks on a line defined by generalized Grover coins
Amrita Mandal, Rohit Sarma Sarkar, Shantanav Chakraborty +1
In this article, we undertake a detailed study of the limiting behavior of a three-state discrete-time quantum walk on one dimensional lattice with generalized Grover coins. Two li…
Quadratic speedup for spatial search by continuous-time quantum walk
Simon Apers, Shantanav Chakraborty, Leonardo Novo +1
Continuous-time quantum walks provide a natural framework to tackle the fundamental problem of finding a node among a set of marked nodes in a graph, known as spatial search. Wheth…
Improved Upper Bounds for the Hitting Times of Quantum Walks
Yosi Atia, Shantanav Chakraborty
Continuous-time quantum walks have proven to be an extremely useful framework for the design of several quantum algorithms. Often, the running time of quantum algorithms in this fr…
On the optimality of spatial search by continuous-time quantum walk
Shantanav Chakraborty, Leonardo Novo, Jérémie Roland
One of the most important algorithmic applications of quantum walks is to solve spatial search problems. A widely used quantum algorithm for this problem, introduced by Childs and…
How fast do quantum walks mix?
Shantanav Chakraborty, Kyle Luh, Jérémie Roland
The fundamental problem of sampling from the limiting distribution of quantum walks on networks, known as \emph{mixing}, finds widespread applications in several areas of quantum i…
Analog quantum algorithms for the mixing of Markov chains
Shantanav Chakraborty, Kyle Luh, Jérémie Roland
The problem of sampling from the stationary distribution of a Markov chain finds widespread applications in a variety of fields. The time required for a Markov chain to converge to…
Finding a marked node on any graph by continuous-time quantum walk
Shantanav Chakraborty, Leonardo Novo, Jérémie Roland
Spatial search by discrete-time quantum walk can find a marked node on any ergodic, reversible Markov chain quadratically faster than its classical counterpart, i.e.\ in a time…
The power of block-encoded matrix powers: improved regression techniques via faster Hamiltonian simulation
Shantanav Chakraborty, András Gilyén, Stacey Jeffery
We apply the framework of block-encodings, introduced by Low and Chuang (under the name standard-form), to the study of quantum machine learning algorithms and derive general resul…
Environment-assisted analog quantum search
Leonardo Novo, Shantanav Chakraborty, Masoud Mohseni +1
Two main obstacles for observing quantum advantage in noisy intermediate-scale quantum computers (NISQ) are the finite precision effects due to control errors, or disorders, and de…
Optimal quantum spatial search on random temporal networks
Shantanav Chakraborty, Leonardo Novo, Serena Di Giorgio +1
To investigate the performance of quantum information tasks on networks whose topology changes in time, we study the spatial search algorithm by continuous time quantum walk to fin…
Spatial search by quantum walk is optimal for almost all graphs
Shantanav Chakraborty, Leonardo Novo, Andris Ambainis +1
The problem of finding a marked node in a graph can be solved by the spatial search algorithm based on continuous-time quantum walks (CTQW). However, this algorithm is known to run…
Systematic Dimensionality Reduction for Quantum Walks: Optimal Spatial Search and Transport on Non-Regular Graphs
Leonardo Novo, Shantanav Chakraborty, Masoud Mohseni +2
Continuous time quantum walks provide an important framework for designing new algorithms and modelling quantum transport and state transfer problems. Often, the graph representing…
Controlled Secret Sharing Protocol using a Quantum Cloning Circuit
Satyabrata Adhikari, Sovik Roy, Shantanav Chakraborty +3
We demonstrate the possibility of controlling the success probability of a secret sharing protocol using a quantum cloning circuit. The cloning circuit is used to clone the qubits…
Entanglement in the Grover's Search Algorithm
Shantanav Chakraborty, Subhashish Banerjee, Satyabrata Adhikari +1
Quantum Algorithms have long captured the imagination of computer scientists and physicists primarily because of the speed up achieved by them over their classical counterparts usi…
Non-classical Correlations in the Quantum Search Algorithm
Shantanav Chakraborty, Satyabrata Adhikari
Entanglement lies at the heart of quantum mechanics and has no classical analogue. It is central to the speed up achieved by quantum algorithms over their classical counterparts. T…