Speaker
Description
Quantum computing is emerging as a new paradigm for the solution of a wide class
of problems that are not accessible by conventional high performance computers
based on classical algorithms. Quantum computers can in principle e?ciently solve
problems that require exponential resources on classical hardware, even when using
the best known classical algorithms. In the last few years, several interesting prob-
lems with potential quantum speedup have been brought forward in the domain of
quantum physics, like eigenvalue-search using quantum phase estimation algorithms
and evaluation of observables in quantum chemistry, e.g. by means of the hybrid
variational quantum eigensolver (VQE) algorithm.
The original idea that a quantum computer can potentially solve many-body
quantum mechanical problems more e?ciently than classical algorithms is due to R.
Feynman who proposed to use quantum algorithms to investigate the fundamental
properties of nature at the quantum scale. In particular, the simulation of the
electronic structure of molecular and condensed matter systems is a challenging
computational task as the cost of resources increases exponentially with the number
of electrons when accurate solutions are required. With the deeper understanding
of complex quantum systems acquired over the last decades this exponential barrier
bottleneck may be overcome by the use of quantum computing hardware. To achieve
this goal, new quantum algorithms need to be develop that are able to best exploit
the potential of quantum speed-up [1,2]. While this e?ort should target the design
of quantum algorithms for the future fault-tolerant quantum hardware, there is
pressing need to develop algorithms, which can be implemented in present-day NISQ
(noisy intermediate scale quantum) devices with limited coherence times [3,4].
In this talk, we will ?rst introduce the basics of quantum computing using super-
conducting qubits, focusing on those aspects that are crucial for the implementation
of quantum chemistry algorithms. In the second part, I will brie
y discuss the limi-
tations of currently available classical approaches and highlight the advantages of the
new generation of quantum algorithms for the solution of many-electron problems
in the ground and excited states [5].
[1] B.P. Lanyon et al., Nature Chem. 2, 106 (2010).
[2] N. Moll, et al., Quantum Sci. Technol. 3, 030503 (2018).
[3] A. Kandala et al., Nature, 549, 242 (2017).
[4] P. Baroutsos, et al., Phys. Rev. A, 98 022322 (2018).
[5] M. Ganzhorn,, et al., Phys. Rev. Appl., 11 044092 (2019).
