## A QIG seminar on “the Polynomial Hierarchy” by Friederike Dziemba

June 6, 2016

In this post I’d like to share a video we’ve uploaded of a recent talk in the quantum information group seminar series by Friederike Dziemba where she presents a physicist-friendly overview of the polynomial hierarchy, a central idea in computational complexity theory:

If you’d like to see more content like this then please do hit the like button. And if you’d like to keep up to date with content from the quantum information group, Hannover, then please don’t hesitate to subscribe to our channel and my own channel.

## The theory of quantum noise and decoherence, lecture 10

January 27, 2016

The video of my 10th lecture on the theory of quantum noise and decoherence is now available.
Here in lecture 10 I continue the discussion of master equations for quantum dots and introduce a model for the continuous measurement of position:

## Presentations are more important than papers: my first youtube video

July 27, 2015

During the past 5 years or so I have come to believe that presentations are actually more important than scientific papers. As a consequence, I have recently spent quite a lot of energy learning how to give better presentations. This is a truly fascinating and rewarding topic. While I find it is difficult, if not downright impossible, to master good public speaking, I’ve very much enjoyed trying to improve how I give my presentations.

Today I’d like to annouce the appearance of my first youtube video:

This is a recording of a talk I recently gave to graduate students here in Hannover. The objective of the talk was to share and channel advice I’ve received in the past years on how to give a good presentation. While I don’t claim to be especially good at giving good talks myself (the excruciating experience of watching myself on video for essentially the first time only serves to underline this!) I have learnt a great deal from other excellent speakers, and I hope that I can at least share a couple of the tips and tricks I’ve learnt.

Depending on the reception to this video it might signal a change in the way I will go about communicating our research. I’ve recently noticed that I am spending an increasing amount of time watching videos of talks at conferences, video tutorials, and miscellaneous other videos (cat videos, unboxings, etc. 🙂 ). It truly is a supremely powerful medium of communication, combining both visual and auditory modes of delivery, and, given that you can pause and skip, I have found it to often be superior to attending talks.

I am still passionate about open science, and open notebook science, and I am always contemplating better and more efficient ways to implement at least some core principles of openness. This is why this blog and my twitter account have become so neglected as of late: I’ve just found that github provides an amazingly useful, superior, and simple tool to achieve this. If you want to know what I’m doing on any given day then you can check out my activity there. (Basically all of my notes are now stored openly there.)

However, github is not the right tool for communicating and sharing ideas. Here I think video is superior, and youtube a natural platform. We’ll see.

I do hope you enjoy watching my video; any comments, suggestions, and criticisms are (actually) welcome!

## Antrittsvorlesung

June 9, 2011

On Tuesday June 7th I gave my Antrittsvorlesung (= inaugural lecture) entitled “Größenverhältnisse und Information” (= “Scale and information”). You can find the slides here. The german text of the lecture can be found here and the english text here.

## QUEST special lecture 3 and the COQUIT conference

November 23, 2010

I’ve been a little distracted with a conference we hosted last week (see here for the program), so I didn’t get around to loading the slides for the last of the QUEST special lectures. My dilly-dallying has meant that I can kill two birds with one stone: the talk I gave at the COQUIT conference was essentially identical to the third special lecture. I attach the slides here, if you’re interested.

## QUEST special lecture 2

November 4, 2010

Yesterday I gave the second of three QUEST special lectures. I discussed the variational principle in the context of quantum spin systems and spoke about the problems and some solutions associated with its application. You can find the slides here.

## QUEST special lecture 1

October 28, 2010

Yesterday I gave the first of three QUEST special lectures. You can find the slides here. Readers of this blog will be familiar with the content: I talked about the simulation problem and hamiltonian complexity and ended with the result that the dynamics of a 1D quantum spin system can be efficiently approximated (by a quantum cellular automaton) for $|t| \sim \log(n)$.

In the next lecture I’ll show how to turn this result around and use quantum circuits to simulate the statics and dynamics of strongly interacting quantum systems via the variational principle.