Reiter, Florentin

Date:  Wednesday, July 23, 2017
Time: 11:00
Place: ETH Zurich, Hönggerberg, HPF G 6
Host:  Jonathan Home

A Tale of (Engineered) Dissipation: From Entanglement Generation to Quantum Error Correction for Metrology

Florentin Reiter
Harvard University, Cambridge, USA

Quantum information processing is to a large extent performed using unitary gate operations which are affected by decoherence and dissipation. This imposes limitations on possible quantum information tasks. Since the first proof-of-principle proposals for ‘quantum reservoir engineering’ [1], the idea of engineering dissipation to play an active role in quantum information tasks has developed into a new paradigm [2], which bears the potential to overcome problems of unitary quantum information processing. Numerous theoretical proposals have studied the dissipative preparation of interesting quantum states, and advantages over previous methods have been identified [3]. Pioneering experiments have demonstrated the feasibility of the approach [4].

More recently, engineered dissipation is also used in more general quantum information tasks, such as quantum error correction. In my talk, I will present a quantum error correction scheme that harnesses dissipation to stabilize a qubit [5]. In our approach, always-on couplings to an engineered environment protect a two-dimensional code space against spin or phase flips. The protocol operates in a fully autonomous manner without the need to perform measurements or feedback operations. The scheme can be implemented in systems of trapped ions and can be used for improving high precision sensing. In a broader context, this work constitutes a stepping stone towards the paradigm of self-correcting quantum information processing.

_{[1] J. F. Poyatos, J. I. Cirac, and P. Zoller, Phys. Rev. Lett. 77, 4728 (1996); M. B. Plenio, S. F. Huelga, A. Beige, and P. L. Knight, Phys. Rev. A 59, 2468 (1999).
[2] B. Kraus, H. P. Büchler, S. Diehl, A. Kantian, A. Micheli, and P. Zoller, Phys. Rev. A 78, 042307 (2008); F. Verstraete, M. M. Wolf, and J. I. Cirac, Nat. Phys., 5, 633 (2009).
[3] M. J. Kastoryano, F. Reiter, and A. S. Sørensen, Phys. Rev. Lett. 106, 090502 (2011); F. Reiter, D. Reeb, and A. S. Sørensen, Phys. Rev. Lett. 117, 040501 (2016).
[4] Y. Lin, J. P. Gaebler, F. Reiter, T. R. Tan, R. Bowler, A. S. Sørensen, D. Leibfried, and D. J. Wineland, Nature 504, 415 (2013); S. Shankar, M. Hatridge, Z. Leghtas, K. M. Sliwa, A. Narla, U. Vool, S. M. Girvin, L. Frunzio, M. Mirrahimi, and M. H. Devoret, Nature 504, 419 (2013).
[5] F. Reiter, A. S. Sørensen, P. Zoller, and C. A. Muschik, arxiv:1702.08673 (2017).}