WEBVTT 00:01.600 --> 00:08.160 Thanks so much. So. Um, yeah. So I was, uh, amused, uh, to hear in 00:08.160 --> 00:14.920 Thomas's talk that he called, uh, nine Tesla, relatively small field. Um, uh, 00:14.920 --> 00:21.920 for us, even the Earth field, uh, is, uh, high field. And, uh, so if you, uh, sort of 00:22.040 --> 00:27.720 look at this picture for different fields, for NMR, there is high intermediate low field. But but 00:27.720 --> 00:34.240 where we're going to go now is lower than low. Okay. So uh, but first I would 00:34.240 --> 00:41.080 like to thank the organizers for, uh, really essentially a perfect conference. Amazing 00:41.080 --> 00:47.000 science, fantastic food, great location, everything, great interactions, everything is really, really 00:47.000 --> 00:53.720 wonderful. Now, uh, I'm a frequent referee, and I have this bad habit 00:53.760 --> 01:00.720 that, uh, even if the paper is perfect, I need to put have small criticisms. I'd like 01:00.720 --> 01:04.960 to start with the title of the conference, which says. 01:07.600 --> 01:14.160 Something about NMR and MRI, but I think that in the modern MRI is like saying fruit and oranges, 01:14.160 --> 01:20.480 because I think, and correct me if I'm wrong, that there is the big set which is NMR, and then it's 01:20.480 --> 01:27.120 divided into different things like MRI and spectroscopy. So and the other and the other thing 01:27.160 --> 01:33.719 to pick on is beating Boltzmann that we already heard. You know, Professor 01:33.720 --> 01:40.320 Boltzmann suffered from very bad condition, neurasthenia and 01:40.360 --> 01:47.000 bipolar disorder and suffered so much that eventually killed himself. So maybe next time, 01:47.000 --> 01:53.040 instead of beating Boltzmann, we we can have compassion for Boltzmann. Anyway, with these 01:53.040 --> 01:58.830 comments, I would like to say that, um, This field of zero field 01:59.470 --> 02:06.350 NMR was pioneered by Alex Pines and John Clark. Um, and 02:06.390 --> 02:12.989 unfortunately the the update here is Alex is no longer with us, as you I'm sure heard. Um, 02:12.990 --> 02:19.869 and initially these guys were looking at the zero field NMR using Squids as sensors. And, 02:19.869 --> 02:26.429 and, uh, when we started collaborating with Alex, we started using spin sensors, um, 02:26.830 --> 02:32.589 mostly atomic magnetometers. And now it's moving also towards diamond, as you will hear. So the plan 02:32.589 --> 02:38.630 of my talk, uh, I will remind people in the audience what ZULF zero to ultra low field NMR 02:38.630 --> 02:45.070 is and most importantly say why you would want to do this. Okay. Even if you can, there is always an 02:45.070 --> 02:51.269 important question. Why? Um, uh, this is NMR without magnets. Um, 02:51.910 --> 02:58.110 hyperpolarization is an essential thing, and I will emphasize it many times, and then I will tell 02:58.110 --> 03:04.589 you about several recent things that are happening in Mainz. And one of them is 03:05.110 --> 03:11.589 these measure like if you want, or rather like oscillations that we see at zero field. 03:11.670 --> 03:18.630 So the best way to understand the idea for for ZULF NMR is think 03:18.670 --> 03:25.349 about first a regular NMR. And like many other things like for example, quantum 03:25.350 --> 03:31.589 computation and many other things and any kind of sensing based on spins, 03:32.509 --> 03:38.710 there are three phases in NMR. You need to polarize the nuclei. You need to encode the 03:38.710 --> 03:43.429 information that you are interested in. Be that spectroscopic information or the location of the 03:43.429 --> 03:49.789 spins into the spins, you have to encode that right? And then you need to read it out to 03:49.790 --> 03:56.549 detect. And normally you need magnetic fields, strong magnetic fields for all 03:56.830 --> 04:03.829 three of these stages. And the idea of ZULF NMR is, um, to get rid of the need for 04:03.829 --> 04:09.350 magnetic field in each one of them. Uh, for instance, use hyperpolarization techniques that do 04:09.350 --> 04:15.389 not rely on magnetic field in the polarization stage. Rely on J couplings for your spectroscopic 04:15.390 --> 04:22.309 information in the encoding stage, and use the spin based sensors, uh, for detection. So that's 04:22.309 --> 04:28.309 the the basic idea. And, um. 04:30.869 --> 04:37.829 Uh, just to show you how this looks like. And I must say, uh, when this field was 04:37.829 --> 04:42.670 introduced, people were kind of laughing at it, and they don't laugh anymore. And now you can find a 04:42.670 --> 04:48.549 lot of actually, labs that are trying to do this all over the world. Uh, in India, 04:49.189 --> 04:55.900 Madhu is here in, uh, In China. So this is, uh, to show you an apparatus that was built 04:55.900 --> 05:02.620 already more than a decade ago, uh, in China But this gentleman, Xin Zhou. Uh, 05:02.620 --> 05:08.820 and this is a magnetic field. So, uh, so when you go to the ZULF NMR lab, instead of magnets, you see 05:08.859 --> 05:15.178 magnetic fields because the Earth's field is too high. And, uh, he, of course, learned it, uh, as a 05:15.179 --> 05:21.099 postdoc in the Pines group, uh, several years before that. Um, 05:22.140 --> 05:28.699 so, okay, now, uh, we've learned to do it, but why do we do it? Okay, that's an important question. And 05:28.700 --> 05:35.619 I'll give you a short list here. Uh, it it is, uh, not necessarily super 05:35.619 --> 05:41.979 inexpensive and portable, but it can be made that as we heard in Michael Taylor's talk, uh, yesterday, 05:42.420 --> 05:49.140 um, the other more physical thing that allows you, uh, the access to couplings that are truncated in 05:49.140 --> 05:55.859 the normal NMR experiment due to the large Zeeman term. Because the frequencies are 05:55.859 --> 06:02.739 low, you are not limited by by the skin effect, and you can actually do measurements inside metal 06:02.739 --> 06:08.939 containers, which is practically important. It is completely insensitive to sample 06:08.980 --> 06:15.659 inhomogeneities because if the field is zero it's okay. Yeah that's okay. And 06:15.660 --> 06:22.539 then, uh oh, there's some strange, uh, sorry about this. Uh, so there 06:22.540 --> 06:29.499 are certain, um, spin states, uh, that are long lived at Zero Field. For example, there is 06:29.500 --> 06:35.059 this whole concept of hetero nuclear spin singlets with long lifetime, which are not 06:35.059 --> 06:41.900 possible, uh, at higher fields, um, and, uh, in certain cases 06:41.900 --> 06:48.019 there is enhanced relaxation contrast for, for relaxometry applications. So all of these things tell 06:48.019 --> 06:54.699 you that, uh uh, you know, you can kind of. Not really. You can never. I'll explain. 06:54.899 --> 07:01.259 Used to emphasize that we are not here to compete with with with high field NMR but we are 07:01.260 --> 07:08.139 to find niches where we can be complementary. So that's the main idea. All right. And I 07:08.140 --> 07:14.939 always like to say that if, uh, for most NMR people, hyper hyperpolarization is a luxury, you 07:14.940 --> 07:20.099 have a small signal and you want to make it bigger. Right. That for for ZULF it's actually a 07:20.099 --> 07:25.940 necessity because, uh, the polarization is zero. Uh, thermal polarization is zero. 07:26.780 --> 07:33.659 So, uh, there are many, uh, hyperpolarization techniques. And I would like to advertise a 07:33.660 --> 07:40.380 relatively recent review with many names, uh, that you will recognize here. Like, for 07:40.380 --> 07:46.689 example, the previous speaker and, uh, James Eills who is here in the audience, etc. 07:46.730 --> 07:53.729 and this project was spearheaded by, uh, eager content reviews. Uh, actually, 07:53.729 --> 08:00.089 all the, uh, techniques that we knew about at the time of writing, which is not so long ago. 08:01.569 --> 08:08.409 Now, this is a diagram. I like this sort of tells you about 08:08.410 --> 08:14.489 this, the status of the field of zero field NMR. And, um, you see, the 08:14.490 --> 08:20.889 hyperpolarization is the enabling thing for zero field NMR. And, and we 08:20.890 --> 08:26.890 actually tried all of these. The green here means that, that things that have already been tried and 08:26.890 --> 08:32.489 demonstrated to work And you see here from anywhere from Halbach brute force polarization to 08:32.530 --> 08:38.769 various kinds of hydrogen polarization,etc., etc. photo 08:38.770 --> 08:45.209 CIDNP. And uh, the one thing that we are working towards but haven't yet demonstrated the 08:45.210 --> 08:51.049 stochastic, uh, polarization. Uh, for detection. Um, 08:52.169 --> 08:58.849 so you can, uh, do inductive detection, for example, do a zero field, uh, experiment and then shuttle 08:58.849 --> 09:04.209 into high field magnet and do detection. Sometimes we do that, uh, squid optically pumping 09:04.210 --> 09:10.809 magnetometers, uh, anisotropic magneto resistive sensors, very inexpensive, not so 09:10.810 --> 09:16.690 sensitive, but we have several, uh, papers demonstrating NMR detection. The recent one 09:16.690 --> 09:22.889 is ZULF NMR detection. Uh, you can find it on the archive. Uh, and now I will show you I'm 09:22.890 --> 09:29.129 very happy to report that zero field NMR can also be detected with diamond. Uh, Dominik. Uh, 09:29.770 --> 09:36.169 and, uh, what we're working on that has not been demonstrated yet, but in the works is the 09:36.250 --> 09:43.169 radioactive detection. So the the idea is to combine uh, uh, A beta NMR gamma 09:43.169 --> 09:49.369 NMR with zero field NMR to sort of compensate for weak 09:50.289 --> 09:56.488 features of both techniques to make a more powerful team. But this isn't in the works. Uh, then, um, 09:56.489 --> 10:03.209 there are various, uh, associated techniques, uh, that have been demonstrated polarization transfer, 10:03.210 --> 10:09.729 relaxometry, partially aligned samples to bring back, for example, dipole 10:10.010 --> 10:16.808 interactions, 2D methods, and what has not been done yet 10:16.809 --> 10:22.890 is single molecule ZULF NMR, which we also call extremum NMR. And that's in the works. And the 10:22.890 --> 10:29.889 radioactively detected NMR. And as we just heard from from Thomas. New 10:29.889 --> 10:36.609 techniques new apparatus leads to new applications. It's driven creation of the 10:36.609 --> 10:42.879 apparatus is driven by the need. But then when you make an apparatus you find new needs. so there 10:42.880 --> 10:49.679 is a lot already that has been done here., quadrupole or nuclear 10:49.960 --> 10:56.039 catalysis, chemical dynamics, fundamental physics applications, search for exotic interactions, 10:56.039 --> 11:01.759 quantum control. And now we are moving towards chirality which is also very exciting. 11:02.719 --> 11:09.199 Um, let me now, uh, give you a brief, uh, sort of sampling of some recent work in the last couple 11:09.240 --> 11:15.960 of years in our lab. Uh, and, uh, so first, 11:15.960 --> 11:22.399 uh, we worked towards this for several years, and this was not very easy, but we we really wanted to 11:22.640 --> 11:29.440 detect zero field signals with diamond sensor. And, um, so finally, 11:29.440 --> 11:36.239 this was possible, uh, using, uh, hyperpolarization, uh, of here, 11:36.320 --> 11:42.880 uh, technique. And so, um, acetonitrile has um, um, 11:43.040 --> 11:49.880 has sort of these two sets of J coupled, uh, lines. So it gives signals 11:49.880 --> 11:56.880 that, uh, one and two, uh J. Uh, and we make this, uh, 11:56.880 --> 12:03.359 polarization in situ inside the apparatus. And we have a on the one side, uh, our well 12:03.400 --> 12:08.679 drafted optical pumping magnetometer as a detector. And on the other side, we have our 12:08.679 --> 12:15.599 diamond, uh, endoscope. Um, and this is kind of a universal, uh, devices and ensemble, uh, 12:15.599 --> 12:22.599 magnetometer that was also used, incidentally, to measure the magnetic field from the heart of 12:22.599 --> 12:28.840 patients and so on. So it's a stick, uh, about a centimeter in diameter, and it's 12:28.880 --> 12:35.639 engineered for, um, sensitivities of around ten pico Tesla per root uh, Hertz 12:35.680 --> 12:42.599 and, um. Here you can see the pulse sequence, 12:42.599 --> 12:49.479 which consists of, uh, bubbling and initiation pulse, and then the detection, uh, and, uh, 12:49.479 --> 12:56.439 this blue signal is the very nice signal to noise detection with 12:56.440 --> 13:02.919 the q spin, optical, optically pumping pump, magnetometer, and, uh, this creepier signal is 13:02.919 --> 13:08.079 diamond. But we, you know, we're very happy that we actually are seeing unambiguously these 13:08.080 --> 13:13.919 resonances. this is just the beginning. It's going to get better. And, of course, uh, the idea for 13:13.920 --> 13:19.040 diamond is a combination of sensitivity and spatial resolution. So this this is a way to to 13:19.080 --> 13:25.719 eventually shrink this apparatus. Uh, enormously. So this was an effort of many 13:26.119 --> 13:32.639 people. So you see, James, uh, here in the audience probably, I don't know, maybe he keeps my talk, I 13:32.640 --> 13:39.589 don't and many others. Okay. Um. All right. Um, so, 13:41.310 --> 13:47.950 uh, another application that we've been working on, uh, is, uh, a ZULF NMR technique for, um, 13:47.950 --> 13:54.269 measuring batteries. And this is nondestructive, uh, measuring, uh, measurement of, uh, 13:54.309 --> 14:00.989 batteries, small batteries with, uh, um, metal, uh, within 14:00.990 --> 14:07.630 metal enclosures. And, uh, this was proposed by John Blanchard many years ago, but, uh, has undergone 14:07.630 --> 14:13.309 many different iterations, uh, in the past. so there is a very nice, uh, collaborative 14:13.310 --> 14:20.189 collaboration of, uh, many people, uh, here, uh, uh, uh, achieved the 14:20.190 --> 14:27.150 measurement of both the analyte, uh, and um,uh, and,uh, and the 14:27.150 --> 14:32.390 solvent. And this is done in this case by shuttling the battery between the Halbach array 14:32.390 --> 14:38.749 and the zero field measurement device. So these are the two students Anne Fabricant and Roman 14:38.750 --> 14:45.509 Picazo-Frutos who were instrumental here. And this is Alexej Jerschow 14:45.630 --> 14:51.389 from European University who is a frequent visitor to our lab and a very dear collaborator. Um, 14:52.150 --> 14:57.309 so the key point here that we measured, uh, through metal enclosure, both electrolyte and 14:57.310 --> 15:04.150 solvent, and use the Halbach prepolarization. And now I'm going to tell you about the 15:04.150 --> 15:10.949 latest thing we are excited about. And we didn't really want to call it a maser or a 15:11.269 --> 15:17.589 raser or whatever. We. So we just called it quantum oscillator. And this is just recently 15:18.150 --> 15:24.909 published on the aircraft so far. Um, and so what we have again is 15:24.909 --> 15:31.469 a self oscillation at the uh, j coupling frequencies at zero 15:31.550 --> 15:38.509 field, and this is similar to two rasers except that zero field. Like I said, and it's 15:38.510 --> 15:45.429 also similar to what has been demonstrated recently with xenon spin 15:45.750 --> 15:52.229 based hyperpolarizationXENON and space spin masers in, for instance, in 15:52.270 --> 15:58.629 HAFAI by our collaborators there, and something that's called the Floquet maser. But the 15:58.629 --> 16:05.429 distinguishing feature is that it's coupling frequencies and can go really to very low micro 16:05.429 --> 16:12.110 hertz frequencies, you know, so it's very, very slow oscillations and up to 16:12.150 --> 16:18.109 tens of hertz could be higher if you need. Um, there is a popular 16:18.910 --> 16:25.229 misconception that these kind of systems require population inversion. They don't. Uh, and the idea 16:25.230 --> 16:30.779 is that you have a feedback, so you have some electronics so you can get energy from there. But 16:30.780 --> 16:37.420 you do need non-equilibrium. Population that you need polarization, 16:37.620 --> 16:44.460 that's for sure. Um, so, uh, we as you will see. It works with many different, 16:44.460 --> 16:51.380 uh, molecules, um, the different types. Uh, it makes lines narrow and may have 16:51.419 --> 16:58.299 helped to resolve, uh, blended lines, but, um. Uh, there are some complications I will 16:58.300 --> 17:05.059 mention in a minute. And it may allow on demand spectral editing, which is also quite exciting. 17:05.619 --> 17:12.060 Uh, so this is the experiment. Uh, the idea is that you 17:12.339 --> 17:19.339 measure, uh, ZULF NMR signal, in this case with an atomic magnetometer, and then you apply a 17:19.339 --> 17:26.219 feedback. And in this case, there is only one, uh, axis that is available. So you apply the feedback 17:26.219 --> 17:33.219 on the same axis, where you have your signal and you have a computer, 17:33.420 --> 17:40.219 and you can synthesize what kind of feedback you may have. And there are two main parameters for 17:40.220 --> 17:46.978 this. Uh, feedback is a delay. And again you can play with. And here again this 17:47.019 --> 17:53.739 J and two J um uh transitions for instance in a Sydney nitril 17:53.780 --> 18:00.579 And this is uh, a hydrogen, uh, polarization that we use. 18:02.060 --> 18:08.459 Okay. Uh, so here is for, for reference, uh, a free, uh, 18:08.459 --> 18:15.179 decay, uh, signal at zero field. Uh, so without the oscillation and then we 18:15.300 --> 18:22.099 apply the feedback, uh, here at t equal to zero. And then you see that there is 18:22.099 --> 18:27.969 some characteristic dynamics. After some time the oscillation starts and this can be actually 18:28.290 --> 18:35.248 accurately calculated. And then. And then you have the system reaching the steady state, 18:35.730 --> 18:41.728 um steady state condition. And then there is slow decay due to the decay of the 18:42.170 --> 18:48.529 polarization, the relaxation of the polarization. And you see here, uh, where the transitions 18:48.810 --> 18:55.769 are expected. Uh, in this case, we expect them at a very 18:55.770 --> 19:01.689 low frequency, 1.7Hz. And around here three point something. And you see that there is an 19:01.689 --> 19:07.849 oscillation at only one frequency under these conditions, okay. And not at the other with this 19:07.849 --> 19:14.448 choice of the delay and and gain. And now you can do it in a variety of 19:15.369 --> 19:22.009 conditions. And in some cases, uh, you can see, um, that you can have oscillation of 19:22.209 --> 19:28.968 both J and two J, and in some cases only on one of them, either one of them And I would like to 19:29.969 --> 19:36.929 draw your attention to, to these solid lines here. These are analytical calculations that reproduce 19:36.930 --> 19:43.688 what is happening here that were done by our brilliant, uh, PhD student, uh, 19:43.689 --> 19:50.289 Jingyan Xu. Um, yeah. So, 19:50.610 --> 19:55.848 uh, I guess I already said depending on feedback parameters, you can have only one or both of of 19:55.849 --> 20:02.449 lines. And we have the analytical model. Okay. So this is, uh, now various, uh, 20:02.449 --> 20:09.249 molecules. And uh, we shouldn't, I guess, spend time looking at the details. But one 20:09.729 --> 20:16.609 thing is that, um, the correspondence of your oscillation lines to, to, 20:16.810 --> 20:23.609 you know, your, um. A lot 20:23.609 --> 20:30.569 of lines without feedback is a is a bit, uh, complex. Uh, but in general the lines 20:30.569 --> 20:37.209 that you see are, uh, narrower and uh, it applies to, um, uh, 20:38.329 --> 20:44.769 applies to many molecules and allows for spectral simplification. Um, but uh, one needs to be a bit 20:44.769 --> 20:49.848 careful. And this is what we are working on right now to learn to extract actually the chemical 20:49.849 --> 20:56.688 information, uh, in the presence of effects like resonance pooling. Um, multiple oscillation points 20:56.689 --> 21:03.569 for one system. Uh, so lines appearing at different values of the delay and gain and uh, uh, and 21:03.609 --> 21:09.529 nonlinear interaction. So I would like to avoid overselling this to you. We are very excited. But 21:11.009 --> 21:17.969 but. Okay. And then so I'm kind of proud of, uh, of this, uh, experiment, uh, because here 21:17.969 --> 21:24.599 we wanted to separate the effects on this J oscillators of chemistry 21:24.759 --> 21:31.759 versus isotopic enrichment. And so we prepared several samples 21:31.760 --> 21:37.999 containing pyridine and from pyridine. As you see here. And we 21:37.999 --> 21:44.719 always have basically a mixture of say 5050 of the two, um 21:45.280 --> 21:51.920 compounds. But sometimes we have for example from pyridine in this case is fully 21:52.280 --> 21:58.879 labeled with N15 and pyridine is unlabeled. And in the opposite case we will 21:58.880 --> 22:04.759 have um again the same 5050, but some pyridine will be unlabeled, but pyridine will be 22:04.759 --> 22:11.519 labeled. then we can see what happens. And so these are again uh, uh of the of the 22:11.520 --> 22:18.199 feedback. And you see for example, some pyridine lines basically do not really do much when you 22:18.199 --> 22:24.719 change the game. Maybe there's a little bit of an effect. And when 22:24.719 --> 22:30.958 you add up now half of labeled pyridine, you see that there is some 22:30.959 --> 22:37.759 effect. So now you see some dependance of the frequency on the gain. And if you mix them 22:37.800 --> 22:44.519 equally, then you see some kind of an effect that looks like, uh, a avoided level crossing 22:44.920 --> 22:51.639 in this case. Um, and, and then eventually the farm pyridine disappears. So this is to say that it's 22:51.640 --> 22:58.400 an interesting, uh, rich dynamics that we are currently studying, um, that we hope, 22:58.480 --> 23:03.600 um, can result in, in a very good, um, selective method for chemistry. 23:06.280 --> 23:12.879 Um, okay. The detail theory is now currently under development, 23:12.880 --> 23:19.480 so I wanted to show you this thing here. So this is a selection of, of the 23:19.480 --> 23:26.439 experiments that we are doing. So and we ZULF here uh, J oscillators, uh, 23:26.520 --> 23:33.400 spin amplifiers and other thing we're doing. Um, and um, uh, we have 23:33.400 --> 23:40.198 an experiment where we are working with ZULF NMR of living cells, uh, the Hela 23:40.199 --> 23:47.160 cancer cells. have a postdoc who is an expert on, on that. And, and so for these, uh, what 23:47.160 --> 23:54.039 is the what is absolutely essential. And you cannot do any work if you don't have very good 23:54.079 --> 24:00.879 hyperpolarization. And so, for instance, these guys, this is Raphael Kircher, the senior. Um, 24:01.359 --> 24:07.559 he's a he's a he's a postdoc. And Jingyan are very good at, um, different 24:07.560 --> 24:12.439 chemistry. So you can see there's different molecules, different levels of polarization, 24:12.439 --> 24:19.029 different Enrichment. Um, so, uh, the the key 24:19.030 --> 24:25.989 points of this is, uh, a technique that, uh, hyperpolarization, uh, is enabled, 24:25.989 --> 24:32.709 and it's a novel platform. This this is the star is to remind me not to oversell it because, uh, 24:33.030 --> 24:38.229 you know, people have worked with self oscillating systems for a long time, and there are a lot, lots 24:38.230 --> 24:44.229 of analog systems But this is novel in the sense that it's at zero field and purely J coupling 24:44.269 --> 24:49.789 transition And it's for chemistry, nonlinear dynamics, fundamental physics and who knows what 24:49.790 --> 24:56.469 else. So all right, so, um, now, uh, I want to make good on 24:56.470 --> 25:02.989 the, uh, homework that the organizers, uh, gave us and, uh, give some thoughts 25:02.990 --> 25:09.789 about the, uh, miniaturization. Uh, I think that, uh, ZULF uh, 25:09.869 --> 25:16.589 is a very good candidate for Lab ona Chip.Okay. And we many 25:16.589 --> 25:23.349 people here work on Lab on a Chip. Um, and um, also there is a whole program at the National 25:23.589 --> 25:30.108 Standards and Technology in the US called nest on the chip. Um, and I think that there is no, nothing 25:30.109 --> 25:36.309 that prevents this from, from being realized except, uh, engineering and investment. So I don't 25:36.310 --> 25:43.188 see any technological problems to shrinking it, um, uh, to, to a chip uh, 25:43.189 --> 25:49.029 scale. Um, so the fact that there are no magnets, I think facilitates 25:49.029 --> 25:55.709 miniaturization, uh, microfluidics in this context, as was mentioned before, was done already. Uh, 25:55.749 --> 26:02.228 see, in our lab, um, in 2008, uh, there are many applications 26:02.270 --> 26:08.789 catalysis, batteries, plants, uh, uh, relaxometry oil cells, etc. 26:10.310 --> 26:17.149 And I just wanted to again advertise this recent review that already was mentioned 26:17.150 --> 26:22.869 by some people. And there is actually some chapters, some parts that talk about possible 26:22.870 --> 26:28.949 miniaturization direction. If you are interested, this is the recent review of Zero field and the 26:28.949 --> 26:35.229 NMR. So this brings me to the end. Our lab has existed in 26:35.230 --> 26:41.149 mines for the last 11 or so or ten and a half years. And, um, 26:41.709 --> 26:48.709 originally it was John Blanchard, uh, and I who put it all together. And we have, 26:48.949 --> 26:55.709 uh, very many, uh, absolutely brilliant alumni. You see them here. We have a 26:55.710 --> 27:02.109 wide network of collaborations in different countries and, and in Germany. 27:02.910 --> 27:09.819 And currently this is who is in the ZULF lab. but there is. You know, 27:10.019 --> 27:16.739 uh, dynamics, uh, people, people grow and, uh. Uh, Danila Barsky, 27:17.180 --> 27:24.019 um, um, is moving now for a faculty position. Uh, the University of Miami. 27:24.220 --> 27:30.620 Uh, and Fabricant got a permanent position at the PTB Berlin straight from 27:30.979 --> 27:37.659 graduate school. And, um, Ramon Picasso Frutos just started his position as a 27:37.660 --> 27:44.539 senior scientist at envision. The rest of us are still there, and Alexej visits us often, 27:44.540 --> 27:51.540 and we're really happy about it. Um, so if you want a brief in the unlikely case, uh, 27:51.540 --> 27:57.939 you got interested by my talk and want a brief introduction to the field. Then there is a short, uh, 27:58.060 --> 28:04.459 review by John Blanchard, Andreas Bissinger, and me from a few years back, and a 28:04.780 --> 28:10.938 rather detailed Field review that already was mentioned before. Um, for 28:11.540 --> 28:17.779 those of you who are interested in molecules, fundamental physics, 28:17.780 --> 28:24.660 and applying NMR to fundamental physics, I would like to advertise a workshop that I 28:24.660 --> 28:30.859 think is going to be extremely exciting. It's a very violation in molecules that we're going to 28:30.859 --> 28:37.619 have about on March 30th through April 1st. Okay. So and there will be 28:37.660 --> 28:44.139 we're going to be reporting some very exciting, uh, results on uh, trying to get towards parity 28:44.180 --> 28:50.139 violation, uh, in the transitions in chiral molecules. Uh, so 28:50.540 --> 28:57.539 please consider coming there. And, um, the plan of my talk, uh, 28:58.059 --> 29:05.020 uh, is here. Um, hyperpolarization is a bucket of spins is what we need. Uh, And this 29:05.020 --> 29:11.819 is the eye view of your miniature NMR MRI. And this is set in a 29:11.819 --> 29:18.099 beautiful island setting, uh, as well. And, uh, thank you very much for your attention. Yeah. 29:26.140 --> 29:31.180 Yeah. Thank you very much for that wonderful talk. Um, yeah. Are there any questions? 29:34.219 --> 29:41.179 Marcel? You want to go first again? Uh, yeah. Sorry for being such a loud mouth, but, 29:41.180 --> 29:48.139 uh, it's just too, uh, too, too much fun. Too, too interesting. Um, for I've had conversations 29:48.139 --> 29:54.899 with Sara and along these lines as well. So for systems where you, uh, feedback 29:54.980 --> 30:01.739 the, the readout, uh, into the system, um, and at some point, what you 30:01.740 --> 30:08.529 see is very intensely dependent on the parameters of the feedback and less and less dependent on 30:08.530 --> 30:15.489 the properties of the system that your you're studying. So if you use it for as 30:15.489 --> 30:22.170 a spectroscopic technique, in order to actually learn something about the system under study, um, 30:22.210 --> 30:27.769 you tend to start losing the generality that would be required for that. So I was wondering if 30:27.769 --> 30:34.369 you could comment on that trade off. Yeah, that's exactly what we're working on. Um, yeah. So, 30:34.569 --> 30:40.569 uh, this these are if you remove the sample, there are no oscillations. So it's. Yeah. So. Okay. So it's 30:40.569 --> 30:47.209 always it's it's always. It's always, uh, but there are these, uh, 30:47.209 --> 30:54.049 complications. And it's not just, uh, you know, the it also, uh, I believe so we like to talk 30:54.090 --> 31:00.249 about fundamental limits, right? I believe that none of these techniques, people get super excited 31:00.250 --> 31:06.968 It and make statements that, okay, this maser or razer or whatever is, uh, 31:07.849 --> 31:14.810 can, can actually improve your, uh, fundamental sensitivity., uh, almost never the case, 31:14.810 --> 31:21.769 but it can be technically extremely useful. Yeah. So while 31:21.769 --> 31:25.809 we're on the topic, you'll be the next to ask a question while we're on the topic of your 31:26.009 --> 31:30.969 J oscillators or similar or analog to the rasers that that I've been working in the past. So the 31:31.009 --> 31:35.609 non linear interactions look exactly like I've been seeing and publishing them over the last years, 31:35.609 --> 31:40.770 with the lines vanishing at higher fields. Same same as the zero field. I'm wondering at what 31:40.770 --> 31:45.809 point do you see the other line disappearing. You showed this nice system was the two pyridine 31:45.810 --> 31:51.529 versions. Right. And what where is the trade off in the concentrations and what concentration? Do you 31:51.530 --> 31:56.489 not see the second line anymore? Say at, I don't know, at least 5% of the time, I don't know what to 31:56.489 --> 32:02.010 tell you when the lower the concentration at some point. The line disappears, but I don't know what. 32:02.050 --> 32:08.289 It's not nonlinear. Enhanced. It's linearly the same. I don't know. It's very fresh. It's like 32:08.330 --> 32:15.209 basically weeks, all the work. So we are going to to study and the, the encouraging thing 32:15.209 --> 32:21.968 is that Jingyan in his model reproduces all the details. So, um, at some point when we trust it 32:21.969 --> 32:27.289 enough,we, we can do numerical experiments first and then., yeah, it's surprisingly predictable, 32:27.329 --> 32:34.129 right? And those are unpredictable. Yeah. Yeah, yeah. Thank you so much. Um, I think you are next. Thank 32:34.129 --> 32:40.128 you very much. Do you think you can characterize the performance of the Joscillators, perhaps in 32:40.129 --> 32:46.969 terms of the phase noise? Absolutely. Yeah. In the process, yes. Yeah. Because I and 32:47.009 --> 32:53.809 that range of frequency is readily available with other means by function generator 32:53.849 --> 33:00.399 or so on. So I thought it would be nice if there is an advantage of some 33:00.439 --> 33:06.920 something in terms of something. There's a whole big program of what we want to do, and the phase 33:06.920 --> 33:13.879 noise characterization is one of the items on the list. All right. I have 33:13.879 --> 33:20.879 a question as well. Yeah. Go ahead Jan. Yeah. Um, the for somebody not not working in this area. Right. 33:20.919 --> 33:27.400 And I'm going to read those papers you recommended, but, uh, just to get a feeling for it. I 33:27.400 --> 33:33.959 mean, you need hyperpolarization so that you actually will have 33:33.959 --> 33:40.759 something to measure. Yeah. Okay. But now, um, depending on how successful that is or how 33:40.840 --> 33:47.759 how what? Whichever version you use, what kind of sensitivity 33:47.799 --> 33:54.159 limits do you have? I mean, the detectors you showed us were were very sensitive detectors, I 33:54.160 --> 34:00.399 guess. Yeah. Yeah. So since the DVD, uh, is not is not the 34:00.400 --> 34:07.319 strongest feature of these things. Uh, so far at least. Uh, so, um, in the paper, we 34:07.360 --> 34:14.199 we make a comparison, for example, of the sensitivity of, um, uh, kind of tunes from the NMR 34:14.199 --> 34:20.759 setup and the Magritek benchtop,and, and we find that, um, the Magritek wins 34:20.760 --> 34:27.320 by over an order of magnitude, uh, uh, in the sensitivity. that so far, at least, 34:27.360 --> 34:33.999 um, but, um, you can't combine everything in one thing. So we feel 34:33.999 --> 34:40.479 that, uh, the interesting things we can access, uh, imaging within metal 34:40.480 --> 34:46.759 containers and so on, um, chemical dynamics, catalytic dynamics and so on, 34:47.120 --> 34:54.120 uh, is worthwhile. So, yeah. No, it's just that if you want to, if you want to develop an application, and 34:54.159 --> 34:59.959 I'm trying to figure out in my head if there's a. If there's a window of opportunity here, if one 35:00.159 --> 35:04.879 then then sensitivity will be a very important issue because that has to work in the environment 35:04.879 --> 35:10.360 where you have to apply it. Right. Of course. And and so the one one of the things to overcome the 35:10.360 --> 35:15.440 sensitivity limitation is a fantastic hyperpolarization. And that's a therefore this is 35:15.440 --> 35:21.319 a major direction in our lab okay. Is to got it okay. 35:23.719 --> 35:30.158 Now you want to go next or you want to ask a question. All right. Yes 35:30.199 --> 35:37.119 please. Yes. Thank you very much. You mentioned with the J r 35:37.479 --> 35:44.199 with the J oscillators, um, frequencies in the range of micro hertz. So this is two 35:44.199 --> 35:50.959 years. So, um, I mean, you need a lot of signal to measure such a oscillation frequency. And if you 35:50.959 --> 35:56.550 can do that, um, could this also work as a sensor in a very different field because we're looking 35:56.550 --> 36:03.229 at very long term fluctuations on the geo and let's say astronomical level. Yeah. That has to 36:03.229 --> 36:08.830 be carefully studied. Right. So we we didn't measure for two years, but we measured for many, 36:08.830 --> 36:15.669 many, many hours. And the micro hertz range probably I have to remember what it is 36:15.870 --> 36:22.869 many micro hertz but already pushing in that direction. Yeah. So it's just very, very slow uh, 36:22.909 --> 36:27.589 oscillation. And we still see the effect, but we will we need to study what we can do with it. 36:29.750 --> 36:36.628 All right. Anything else? If not, I'll have two short announcements. Um, before we 36:36.629 --> 36:43.189 thank our speaker. Um, well, no, let's first, let's first thank Dmitry Budker for this wonderful Talk. I 36:43.189 --> 36:49.269 think that's, uh. All right.