99 citations · 350 across the 12 of their papers we have counts for
12 papers
Pinned QMA: The power of fixing a few qubits in proofs
Daniel Nagaj, Dominik Hangleiter, Jens Eisert +1
What could happen if we pinned a single qubit of a system and fixed it in a particular state? First, we show that this can greatly increase the complexity of static questions -- gr…
Shorter unentangled proofs for Ground State Connectivity
Libor Caha, Daniel Nagaj, Martin Schwarz
Can one considerably shorten a proof for a quantum problem by using a protocol with a constant number of unentangled provers? We consider a frustration-free variant of the QCMA-com…
Anticoncentration theorems for schemes showing a quantum speedup
Dominik Hangleiter, Juan Bermejo-Vega, Martin Schwarz +1
One of the main milestones in quantum information science is to realise quantum devices that exhibit an exponential computational advantage over classical ones without being univer…
Architectures for quantum simulation showing a quantum speedup
J. Bermejo-Vega, D. Hangleiter, M. Schwarz +2
One of the main aims in the field of quantum simulation is to achieve a quantum speedup, often referred to as "quantum computational supremacy", referring to the experimental reali…
Approximating local observables on projected entangled pair states
M. Schwarz, O. Buerschaper, J. Eisert
Tensor network states are for good reasons believed to capture ground states of gapped local Hamiltonians arising in the condensed matter context, states which are in turn expected…
Direct certification of a class of quantum simulations
D. Hangleiter, M. Kliesch, M. Schwarz +1
One of the main challenges in the field of quantum simulation and computation is to identify ways to certify the correct functioning of a device when a classical efficient simulati…
An exponential time upper bound for Quantum Merlin-Arthur games with unentangled provers
Martin Schwarz
We prove a deterministic exponential time upper bound for Quantum Merlin-Arthur games with k unentangled provers. This is the first non-trivial upper bound of QMA(k) better than NE…
An Information-Theoretic Proof of the Constructive Commutative Quantum Lovász Local Lemma
Martin Schwarz, Toby S. Cubitt, Frank Verstraete
The Quantum Lovász Local Lemma (QLLL) [AKS12] establishes non-constructively that any quantum system constrained by a local Hamiltonian has a zero-energy ground state, if the local…
Simulating Quantum Circuits with Sparse Output Distributions
Martin Schwarz, Maarten Van den Nest
We show that several quantum circuit families can be simulated efficiently classically if it is promised that their output distribution is approximately sparse i.e. the distributio…
Preparing topological PEPS on a quantum computer
Martin Schwarz, Toby S. Cubitt, Kristan Temme +2
Simulating of exotic phases of matter that are not amenable to classical techniques is one of the most important potential applications of quantum information processing. We presen…
A constructive commutative quantum Lovasz Local Lemma, and beyond
Toby S. Cubitt, Martin Schwarz
The recently proven Quantum Lovasz Local Lemma generalises the well-known Lovasz Local Lemma. It states that, if a collection of subspace constraints are "weakly dependent", there…
Preparing projected entangled pair states on a quantum computer
Martin Schwarz, Kristan Temme, Frank Verstraete
We present a quantum algorithm to prepare injective PEPS on a quantum computer, a class of open tensor networks representing quantum states. The run-time of our algorithm scales po…