# Press

### Quanten-Computer löst Quanten-Problem :: pro-physik.de

**Quanten-Computer löst Quanten-Problem**

Einfluss von Störungen auf das Ausbreiten eines Quantensystems untersucht.

Source: :: Quanten-Computer löst Quanten-Problem :: pro-physik.de

### Physiker lösen Problem mit Hilfe von Quanten-Computer der TU Dortmund

See the article about our work “Localization-delocalization transition in the dynamics of dipolar-coupled nuclear spins” in the idw – Informationsdienst Wissenschaft online magazine: Physiker lösen Problem mit Hilfe von Quanten-Computer der TU Dortmund

### Physiker lösen Problem mit Hilfe von Quanten-Computer der TU Dortmund

See the article about our work “Localization-delocalization transition in the dynamics of dipolar-coupled nuclear spins” in the Innovation Report magazine: Physiker lösen Problem mit Hilfe von Quanten-Computer der TU Dortmund

### Acting Locally, Reporting Globally: From quantum physics to biology, a new approach to magnetic resonance turns protons into “spies”.

*Acting Locally, Reporting Globally: From quantum physics to biology, a new approach to magnetic resonance turns protons into “spies”. *

Please see the article published in the Interface Magazine of the Weizmann Institute about our work on “Coherent Dynamical Recoupling of Diffusion-Driven Decoherence in Magnetic Resonance“:

elink: **Interface Magazine, Winter 2014: Acting Locally, Reporting Globally.**

### Random – but not quite: exploiting quantum decoherence as a tool for characterizing unknown systems | Seminar

**SEMINAR at IV Quantum Information Workshop – Paraty 2013**

Wednesday, August 14th 2013

See comments of the talk at the Paraty 2013’s Blog: Decoupling system and environment.

**SEMINAR at CBPF, Rio de Janeiro – Brazil, August 20th, 2013**

**SEMINAR at FaMAF, Córdoba – Argentina, August 27th, 2013**

**Abstract**

The ability to understand and manipulate the dynamics of quantum systems that interact with external degrees of freedom is a major challenge for fundamental quantum physics and its diverse applications, e.g., quantum information processing (QIP) or precision measurements. Progress in dynamical decoupling has lead to new ways to “protect” quantum bits from external degrees of freedom. Sometimes, however, a little bit of “recoupling” –i.e., exposure to the unknowns of the surrounding medium– can help. In this seminar, I will present a series of experimental methods implemented in NMR where by varying the “protection” given to the quantum states of ½-spins (qubits) can lead to new tools for characterizing unknown systems. In particular, I will show how Dynamical Decoupling noise spectroscopy can probe the spectrum of the environmental noise in order to find optimal methods for protecting the qubits [1]. In a new twist, I will present a method termed Selective Dynamical Recoupling (SDR), where suitable designed pulse sequence applied to the spins can selectively address specific information from the probed systems. SDR can be used to measure coupling strengths to the environment via oscillatory modulations that can serve for example to probe chemical identities derived from chemical shifts [2]. Alternatively, SDR can be designed to selectively measure the correlation time of the environmental noise where its value can be useful to probe diffusion processes in restricted spaces to extract the sizes of pores or cells in a non-invasive manner [3]. Applications of this new and simple approach can be found in materials sciences and biology and in particular it can be useful for investigating the nature of tissue compartmentalization *in vivo*, in manners which eventually could be useful in human and clinical settings.

[1] G.A. Alvarez, and D. Suter. Phys. Rev. Lett. **107**, 230501 (2011).

[2] P.E.S. Smith, G. Bensky, G.A. Alvarez, G. Kurizki, and L. Frydman. Proc. Natl. Acad. Sci. U. S. A. **109**, 5958 (2012).

[3] G.A. Alvarez, N. Shemesh, and L. Frydman. Phys. Rev. Lett. **111**, 080404 (2013).

### Random – but not quite: exploiting quantum decoherence as a tool for characterizing unknown systems | Paraty 2013

**SEMINAR at IV Quantum Information Workshop – Paraty 2013**

Wednesday, August 14th 2013

See comments of the talk at the Paraty 2013’s Blog: Decoupling system and environment.

**Abstract**

The ability to understand and manipulate the dynamics of quantum systems that interact with external degrees of freedom is a major challenge for fundamental quantum physics and its diverse applications, e.g., quantum information processing (QIP) or precision measurements. Progress in dynamical decoupling has lead to new ways to “protect” quantum bits from external degrees of freedom. Sometimes, however, a little bit of “recoupling” –i.e., exposure to the unknowns of the surrounding medium– can help. In this seminar, I will present a series of experimental methods implemented in NMR where by varying the “protection” given to the quantum states of ½-spins (qubits) can lead to new tools for characterizing unknown systems. In particular, I will show how Dynamical Decoupling noise spectroscopy can probe the spectrum of the environmental noise in order to find optimal methods for protecting the qubits [1]. In a new twist, I will present a method termed Selective Dynamical Recoupling (SDR), where suitable designed pulse sequence applied to the spins can selectively address specific information from the probed systems. SDR can be used to measure coupling strengths to the environment via oscillatory modulations that can serve for example to probe chemical identities derived from chemical shifts [2]. Alternatively, SDR can be designed to selectively measure the correlation time of the environmental noise where its value can be useful to probe diffusion processes in restricted spaces to extract the sizes of pores or cells in a non-invasive manner [3]. Applications of this new and simple approach can be found in materials sciences and biology and in particular it can be useful for investigating the nature of tissue compartmentalization *in vivo*, in manners which eventually could be useful in human and clinical settings.

[1] G.A. Alvarez, and D. Suter. Phys. Rev. Lett. **107**, 230501 (2011).

[2] P.E.S. Smith, G. Bensky, G.A. Alvarez, G. Kurizki, and L. Frydman. Proc. Natl. Acad. Sci. U. S. A. **109**, 5958 (2012).

[3] G.A. Alvarez, N. Shemesh, and L. Frydman. Phys. Rev. Lett. (2013) – in press. arXiv:1305.2794.

### Featured in PRA Kaleidoscope for Vol. 85 Iss.5 (May 2012)

Image from “Iterative rotation scheme for robust dynamical decoupling.” [Gonzalo A. Álvarez, Alexandre M. Souza, and Dieter Suter, Phys. Rev. A 85, 052324 (2012)]