papers

Publications (14)

quant-ph2018

Impossibility of Cloning of Quantum Coherence

Dhrumil Patel, Subhasree Patro, Chiranjeevi Vanarasa +2

It is well known that it is impossible to clone an arbitrary quantum state. However, this inability does not lead directly to no-cloning of quantum coherence. Here, we show that it…

quant-ph2019

The Quantum Strong Exponential-Time Hypothesis

Harry Buhrman, Subhasree Patro, Florian Speelman

The strong exponential-time hypothesis (SETH) is a commonly used conjecture in the field of complexity theory. It states that CNF formulas cannot be analyzed for satisfiability wit…

quant-ph2025

QSETH strikes again: finer quantum lower bounds for lattice problem, strong simulation, hitting set problem, and more

Yanlin Chen, Yilei Chen, Rajendra Kumar +2

While seemingly undesirable, it is not a surprising fact that there are certain problems for which quantum computers offer no computational advantage over their respective classica…

quant-ph2021

Limits of quantum speed-ups for computational geometry and other problems: Fine-grained complexity via quantum walks

Harry Buhrman, Bruno Loff, Subhasree Patro +1

Many computational problems are subject to a quantum speed-up: one might find that a problem having an O(n^3)-time or O(n^2)-time classic algorithm can be solved by a known O(n^1.5…

quant-ph2022

Memory Compression with Quantum Random-Access Gates

Harry Buhrman, Bruno Loff, Subhasree Patro +1

In the classical RAM, we have the following useful property. If we have an algorithm that uses memory cells throughout its execution, and in addition is sparse, in the sense th…

cs.CC2022

Matching Triangles and Triangle Collection: Hardness based on a Weak Quantum Conjecture

Andris Ambainis, Harry Buhrman, Koen Leijnse +2

Classically, for many computational problems one can conclude time lower bounds conditioned on the hardness of one or more of key problems: k-SAT, 3SUM and APSP. More recently, sim…

quant-ph2025

Improved Quantum Query Upper Bounds Based on Classical Decision Trees

Arjan Cornelissen, Nikhil S. Mande, Subhasree Patro

Given a classical query algorithm as a decision tree, when does there exist a quantum query algorithm with a speed-up over the classical one? We provide a general construction base…

quant-ph2018

Non-negativity of conditional von Neumann entropy and global unitary operations

Subhasree Patro, Indranil Chakrabarty, Nirman Ganguly

Conditional von Neumann entropy is an intriguing concept in quantum information theory. In the present work, we examine the effect of global unitary operations on the conditional e…

quant-ph2023

Teleportation of quantum coherence

Sohail, Arun K Pati, Vijeth Aradhya +2

We investigate whether it is possible to teleport the coherence of an unknown quantum state from Alice to Bob by communicating a lesser number of classical bits in comparison to wh…

quant-ph2026

Quantum algorithms for path and cycle containment problems

Arjan Cornelissen, Amin Shiraz Gilani, Subhasree Patro

The quantum query complexity of subgraph-containment problems, which ask whether a given subgraph is present in an input graph , has been the subject of considerable study.…

quant-ph2025

Quantum Search With Generalized Wildcards

Arjan Cornelissen, Nikhil S. Mande, Subhasree Patro +2

In the search with wildcards problem [Ambainis, Montanaro, Quantum Inf.~Comput.'14], one's goal is to learn an unknown bit-string . An algorithm may, at unit cost…

cs.CC2025

Oracle Separations for RPH

Thekla Hamm, Lucas Meijer, Tillmann Miltzow +1

While theoretical computer science primarily works with discrete models of computation, like the Turing machine and the wordRAM, there are many scenarios in which introducing real…

quant-ph2024

Quantum Sabotage Complexity

Arjan Cornelissen, Nikhil S. Mande, Subhasree Patro

Given a Boolean function , the goal in the usual query model is to compute on an unknown input while minimizing the number of queries t…

quant-ph2025

Fine-Grained Complexity via Quantum Natural Proofs

Yanlin Chen, Yilei Chen, Rajendra Kumar +2

Buhrman, Patro, and Speelman presented a framework of conjectures that together form a quantum analogue of the strong exponential-time hypothesis and its variants. They called it t…