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Milestones


Historical highlights

1965 
LTL founded as a low temperature physics laboratory by Professor Olli V. Lounasmaa.
1973 
LTL becomes an independent unit of TKK.
1975 
LTL organizes LT15, the main international conference in low temperature physics.
1980 
Neuromagnetic brain research started.
1994 
LTL is granted Center of Excellence status by the Academy of Finland. LTL is granted by the EU’s HCM program a European Large Scale Facility status in both ultra low temperature physics (ULTI) and Biomagnetism (BIRCH) for 1994-97.
1996 
Academy Professor Olli Lounasmaa retires Professor Mikko Paalanen becomes the new director of the LTL. Nanophysics introduced as a new research direction. LTL selected by IUPAP to host LT22 in 1999.
1997 
Olli Lounasmaa appointed Academician of Science
2003 
LTL established a memorial prize carrying the name of Academician Olli V. Lounasmaa. The first prize was awarded in 2004 to Professor John Clarke from University of California, Berkeley.
2006 
LTL became the home of two national Centers of Excellence (CoE), one in LowTemperature Quantum Phenomena and Devices and another one in Systems Neuroscience and Neuroimaging.
2007 
LTL moved to new premises (Puumiehenkuja 2B) at the end of 2007.
2007 
The graduation of the laboratory’s 100th PhD student.
2008 
Olli V. Lounasmaa's memoirs, titled “Täällä ei näperrellä! – Kylmäfyysikon kuumat paikat”, were published in January 2008 and included a detailed history of LTL.
2008 
12 leading European low temperature laboratories formed a European Microkelvin Collaboration – MICROKELVIN, and received FP7-funding from the Capacities Specific Programme called Infrastructures. MICROKELVIN is coordinated by LTL.
2010 
Riitta Hari appointed Academician of Science

Achievements in ultra low temperature physics

Nuclear spin temperature LTL world records

Superfluid 3He

1972 
Viscosity measurements confirm superfluidity in 3He
1981 
Vortices observed in superfluid 3He
1982 
Vortex core transition found in superfluid 3He-B
1992 
Composite topological object - spin-mass vortex which terminates the soliton - is observed
1993 
Landau's prediction of vortex sheet confirmed experimentally
1996 
Simulation of early universe with the rapid superfluid phase transition in 3He
2000 
Circulation of doubly quantized vortex measured
2002 
Kelvin-Helmholtz instability of the interface between two superfluids is discovered
2003 
An intrinsic velocity-independent criterion for superfluid turbulence is discovered
2006 
Propagating vortex front is observed
2010 
Non-ground-state Bose-Einstein condensates of magnons in superfluid 3He-B are generated

Nuclear magnetism and superconductivity

1983 
Antiferromagnetic ordering observed in Cu at 58 nK
1987 
First Bragg reflection from antiferromagnetically ordered Cu
1989 
Antiferromagnetic ordering in Ag at 560 pK
1990 
Complex phase diagram mapped by neutron diffraction in Cu
1993 
World record temperature of 280 pK in a Rh sample
1994 
Neutron diffraction shows long range nuclear magnetic order in Ag
1999 
World record temperature of 100 pK in a Rh sample
2000 
Influence of nuclear magnetism on superconductivity in Rh
2004 
Nuclear ferromagnetism in Li
2006 
Superconductivity in Li

Interfaces in quantum systems

1991 
Optical measurements in a rotating cryostat below 1 mK
1994 
Optical detection of vortex-free meniscus in rotating superfluid 3He
1995 
Facets on 4He crystals found to be curved
1997 
Facet growth by step motion detected and studied in detail
2000 
3He crystals are imaged at temperatures below 1 mK
2002 
10 new facets discovered on 3He crystal surface
2004 
Quantum roughening of 3He crystals is observed and studied
2006 
Thermodynamics of 4He solid was studied, no non-phonon contribution found
2008 
Devil's staircase of facets observed on 4He crystals.

Brain research

Development of neuromagnetometers


Neuroscientific findings

1982 
MEG signals recorded from second somatosensory cortex.
1983 
Dental-pain-related cortical signals detected with MEG.
1984 
Auditory-cortex origin demonstrated for the auditory mismatch response.
1985 
Magnetic field patterns described and a source model proposed for eye blinking artifacts.
1986 
Long-latency cortical responses demonstrated to painful carbon dioxide stimulation of nasal mucosa
1987 
Cortical origin of 40 Hz auditory responses demonstrated.
Detailed characterization of neuromagnetic responses of the human auditory cortex to on- and off-sets of noise bursts.
New “hei” responses responses demonstrated in the human auditory cortex to vowel onset after fricative consonants.
Cortical origin demonstrated for middle-latency auditory evoked responses.
1989 
Multichannel detection of magnetic compound action fields of peripheral (median and ulnar) nerves.
Neuromagnetic steady-state responses recorded to auditory stimuli, with a proposal for superposition as the generation mechanisms of the large-amplitude 40-Hz response.
The first demonstration of the magnetic mu rhythm in humans.
1990 
Localization of epileptic foci with respect to functional landmarks.
1991 
Demonstration, using the McGurk illusion, that visual input has access to the auditory cortex.
The first demonstration of a 10-Hz auditory-cortex rhythm (“tau rhythm”).
1992 
MEG recordings of different sleep stages.
1993 
Functional organization of the human SI and SII cortices characterized.
Cortical correlates of directional hearing characterized.
A trace of the human auditory sensory memory shown to persist in the cortex for about 10 s.
Functional differences revealed between auditory cortices of the two hemispheres first time by whole-scalp MEG recordings.
1994 
Somatosensory MEG signals detected from posterior parietal cortex.
Demonstration of sensorimotor ~20-Hz oscillatory activity as a specific marker of human motor cortex involvement.
Real-time cortical sequence of language processing (picture naming) described for the first time.
Visual stability suggested to be related to parietal-lobe activation occurring after each eye blink.
An illusion of directional hearing (saltation) described.
1995 
Visual motion area identified with MEG.
Reactivity of the motor cortical 20-Hz activity as a sign of the representation of the voluntary action.
MEG recorded during burst suppression in an anethetized dog.
1996 
Coherence between motor cortex and muscle activity demonstrated at 40 Hz.
MEG signals from deep sources (thalamus, cerebellum, hippocampus) reported.
Dysfunction of letter-string processing revealed in the left occipitotemporal cortex in dyslexia.
Deficit of rapid temporal processing demonstrated in dyslexic adults in a psychoacoustic test (with the saltation illusion).
Temporal-lobe MEG responses to odorant stimuli.
Cortical magnification factor suggested, by means of a simulations study, to result evolutionarily from the animals movement in the environment.
Recording and modeling of the rotating magnetic field patterns to tibial nerve stimulation.
1997 
Cortex–muscle coherence demonstrated at 20 Hz during isometric contraction of upper and lower-limb muscles.
Pain-related right-hemisphere dominance demosntrate. Visual reactivity of occipital and parietal areas dissected.
Involvement of primary motor cortex in motor imagery.
Reactivity of the neuromagnetic 10-Hz rhythm characterized in the human auditory cortex.
Reflections of visual object properties shown in 10-Hz alpha rhythm at a dorsal visual stream area.
Demonstration that omissions of sounds from a regular tone sequence activates the auditory cortex.
1998 
The first direct demonstration of the involvement of the human primary motor cortex in mirroring other persons' actions.
Large-scale cortical reorganization demonstrated in a congenitally deaf person.
A new "parchment-skin illusion" described as a sign of sound-biased touch.
Spatiotemporal description of written word and sentence comprehension.
1999 
Collaborative work with prof. Teuvo Kohonen on the abstract feature maps of the human mind (review).
Delayed cortical activation reflecting reading comprehension demonstrated in dyslexia.
Native language and gender shown to influence auditory cortical processing of simple nonspeech sounds.
2000 
MEG demonstration of the temporal sequence of cortical activation during observation of other person's hand actions.
Characterization of the effect of voice on the speaker’s own auditory cortex.
Abnormal sequence of activation shown in stutterers between left-hemisphere frontal areas involved in speech motor planning and execution.
2001 
Sluggish attentional shifting (SAS) suggested as a core deficit explaining impaired processing of rapid stimulus sequences in dyslexia.
2002
Frequency tagging introduced as a novel means to selectively follow inputs from each ear up to the auditory cortex.
Cortical dynamics of the human mirror-neuron system followed to viewing lip forms.
Different motor cortex involvement demonstrated for verbal and nonverbal mouth movements.
Cortical dynamics of letter-string and face perception dissected in the inferior occipitotemporal cortex.
The cortico-cerebello-thalamic basis of intermittent motor control in humans described.
2003 
Phase locking demonstrated between human primary and secondary somatosensory cortices.
Impaired letter-string processing but normal face processing in the left occipitotemporal cortex shown in dyslexic individuals.
2004 
The human primary motor cortex shown to be activated during observation of tool use.
2005 
Common cortical network shown with MEG for first and second pain (mediated via fast and slow afferents).
Suggestions of pain shown to activate a part of the physical-pain-related brain circuitry.
The first-ever brain activation study of contagious yawning.
Demonstration of forward mechanisms (efference copies) as indicated by suppressed responses to self-triggered sounds in the human auditory cortex.
The first-ever measurement of diffusion tensor imaging and tractography of distal peripheral nerves at 3 T.
2006 
Motor-cortex involvement in visual perception of handwritten letters demonstrated with MEG.
Transient suppression of ipsilateral SI cortex during tactile finger stimulation shown with fMRI.
Combined fMRI and MEG data used to demonstrate dissociation of face selective cortical responses by attention.
Expected linguistic content (top-down) shown to influence processing of isolated spoken syllables in the auditory cortex.
Cortical sequence of word perception described in beginning readers (7-8-year-olds).
2007 
Data-driven analysis of fMRI signals introduced to naturalistic stimulus setups comprising auditory, visual and tactile stimuli.
Intensity of pain seen from another person's face shown to activate the viewer's own emotional pain circuitry.
Actor’s and viewer’s primary motor cortices shown to stabilize similarly after seen (or heard) motor actions.
First-time mapping of real-time functional connectivity among cortical areas in a cognitive task (reading) directly from MEG data.
Review on MEG in the study of language function and dysfunction.
Demonstrated emergence of low-level visual representation in a "wrong" hemisphere due to long and intensive rehabilitation in a cortically blind stroke patient.
2008 
Visual tagging with dynamic noise used to demonstrate that early visual areas reflect the percept of an ambiguous scene (Rubin's vase-face image).
fMRI demonstration that differences between action (verb) and object (noun) naming are determined by image content rather than word class.
Spatial frequency tuning functions measured in the human low-level visual cortices.
2009 
Stimulus-rate sensitivity of human somatosensory fMRI signals predicted by MEG recorded in similar conditions.
Our first "neuroeconomics" study published on brain correlates of competitive ultimatum game.
An extensive review about the brain basis of human social interaction.
Cortical effects of learning new vocabulary demonstrated with MEG.
Direct comparison of fMRI and MEG in action/object naming.
Spatiotemporal convergence of auditory and visual word processing pathways at the level of the word meaning.
Area summation function measured in human primary visual cortex.
Sensitivity for spatial phase information mapped across human visual cortices.
2010 
New ideas proposed about the multiple time scales of human brain functions (review article on brain dynamics and time).
Demonstration that Aδ-fibre stimulation can produce cortical somatosensory responses in a subject lacking large myelinated afferents.
Demonstration of embodied visual perception of distorted finger postures.
Demonstration that observing touch activates human primary somatosensory cortex.
An individual neural marker of successful long-term (10 months) maintenance of new vocabulary in healthy adults.
Demonstration that large-scale interaction of cortical activation patterns may reflect decorrelation.
2011 
Demonstration of important functional differences between MEG and fMRI measures in reading.
Demonstration of the engagement of amygdala in third-person view of face-to-face interaction.

Methodological development

1980 
First 2.5 x 25-m2 magnetically shielded room completed.
1984 
Minimum norm estimates developed.
1984 
4-channel neuromagnetometer in operation.
1986 
Statistical considerations presented about the spatial accuracy and confidence limits of MEG source modeling.
1987 
Isolated problem approach in realistic head models.
1988 
Theoretical calculations about the spatial resolution of neuromagnetic recordings in a spherical model
1989 
24-channel device in operation. Spin-off Company Neuromag Ltd. founded.
1992 
Prototype of 122-channel whole head device in use.
1994 
122-channel magnetometer wins SITRA's (Finland) Engineering Prize. — Temporal spectral evolution method (TSE) introduced.
1996 
Visualization and image processing tools for MEG and MRI integration. — 122-channel magnetometer wins TEK's and TFIFs (Finland) Engineering Prize. — Cardiac MEG artifacts characterized and removed.
1997 
Independent component analysis applied to MEG artifact identification.
1998 
Prototype of 306-channel MEG device ready. New 3 x 4-m2 magnetically shielded room with active shielding concept completed. — fMRI-weighted minimum current estimate developed.
2001
Dynamic imaging of coherent sources (DICS) introduced for extracting neural interactions in the human brain from MEG data.
2002 
Comparison of minimum current estimate and dipole modeling in the analysis of simulated activity in the human visual cortices.
2005 
First multifocal fMRI measurement with quadratic residue sequence and general linear model approach.
2006 
The first physical fMRI phantom designed, built, and tested. — Quantification of mechanical vibration during diffusion tensor imaging at 3 T. — Improved differentiation of tactile activations in human thalamus and second somatosensory cortex using cardiac-triggered fMRI.
2007 
A novel brush stimulator, based on optical fibers, introduced for functional brain imaging.
2008 
A new magnetically shielded room with dedicated stimulators and an upgraded 306-channel neuromagnetometer. — Event-related DICS developed for time-dependent mapping of modulation of rhythmic activity.
2009 
A physical fMRI phantom used to demonstrate that transients may occur in functional magnetic resonance imaging without physiological basis. — Temporal signal-space separation used to effectively remove MEG artifacts from single-trial auditory evoked responses. —
2010 
Analysis of spontaneous MEG activity by means of independent component analysis and a parametric model of brain rhythm reactivity. — Corticokinematic coherence, relying on accelerometer-based motion monitoring, introduced for motor-cortex mapping.

Clinical applications and patient studies

1986 
Cortical activity measured for the first time after stimulation of a multichannel cochlear prosthesis.
1990 
MEG used to pinpoint locations of epileptic foci.
1991 
Cortical responses to bilateral electrical stimulation of a congenitally-deaf ear and an acquired-deaf ear shown to reveal plasticity of the auditory pathways.
Continuous epileptic discharges demonstrated in the auditory cortex of a patient with Landau-Kleffner syndrome.
Auditory evoked responses examined in a group of stroke patients.
1992 
First demonstration that auditory hallucinations in a psychotic person correlate with modified activity of the auditory cortex.
Abnormalities demonstrated in cortical somatosensory magnetic response in patients multiple sclerosis.
Modulation of auditory cortex responses in a patient with temporal-lobe stroke.
Impact of MEG localizaiton of epileptic foci on surgical treatment examined.
1993 
Suppression of magnetic mu rhythm shown to occur during Parkinsonian tremor.
Epileptic mirror focus demonstrated in the parietal cortex on the basis of timing differences.
1994 
Giant somatosensory responses demonstrated in patients suffering from progressive myoclonus epilepsy.
Cortical processing revealed by evoked responses characterized in a patient with a marked hydrocephalus.
MEG evaluation of children and adolescents with intractable epilepsy.
Auditory responses as indicators of cortical plasticity in patients with congenital unilateral hearing loss.
1995 
Ictal MEG recordings during trigeminally triggered facial convulsions.
Abrupt unilateral deafness whon to disrupt auditory pathways.
1997 
Routine clinical studies started in Collaboration with HUCH's. Department of Clinical Neuroscience.
1998 
Brain functions of 13 patients with brain tumor mapped successfully before operation in HUCH.
Correlation of SII-cortex activation with the perception of supernumerous third limbs in a patient after an operated aneyrusm.
Neuromagnetic sequelae of herpes simplex encephalitis.
Modification of neuromagnetic cortical signals by thalamic infarctions.
1999 
Modification of the cortical somatosensory network demonstrated in stroke patients.
Mirroring (and motor-cortex activity) studied for the first time in autistic adults.
PET and MEG localizations of epileptic cortex compared in a group of epileptic patients.
2000
Cortical dynamics desribed in an aphasic patient with deep dyslexia.
Abnormal reactivity of the 20-Hz motor cortex rhythm in patients with progressive myocloluns epilepsy.
2001 
Defective cortical drive to muscle demonstrated in Parkinson's disease and an improvement of the deficit with levodopa.
Three-dimensional integration of brain anatomy and function to facilitate intraoperative navigation around the sensorimotor strip.
Left minineglect demonstrated in dyslexic adults.
Cortical changes after electroconvulsive therapy followed in depression patients.
2002 
Altered central sensorimotor processing demonstrated in patients with complex regional pain syndrome.
Corticomuscular coupling in a subject with mirror movements.
2003 
Impaired mirror-image imitation demonstrated behaviorally in Asperger and high-functioning autistic subjects.
Cortical dynamics of word re-learning tracked in chronic aphasia.
2004 
Abnormal imitation-related cortical activation sequences demonstrated in Asperger’s syndrome.
2007-2010 
Development of preoperative visual cortex mapping pipeline for clinical use.
2009 
Changes demonstrated in brain function and morphology in patients with recurring herpes simplex virus infections and chronic pain.
Reality of auditory verbal hallucinations and the underlying brain circuitry studied in ambulatory hallucinating patients.
Neural processing of spoken words in specific language impairment described with MEG.
2010 
Demonstration of aberrant spatiotemporal resting-state brain activation in patients with chronic pain.

Nanophysics

1994 
Nanothermometer.
1996 
SINIS refrigerator.
1996 
Single electron transistors demonstrated successfully.
1997 
15 nm linewidth demonstrated in electron beam writing.
1998 
8 nm particles and nanotubes moved with the tip of an AFM. Superconductor-insulator transition characterized in a single isolated Josephson junction.
1999 
Carbon nanotube based SET.
2002 
BOT current amplifier (Science 2003).
2003 
Sluice Cooper pair pump.
2004 
L-SET.
2005 
C-SET.
2008 
SINIS turnstile.
2010 
SQUIPT magnetic field sensor.

Cryoengineering

1971 
Cryostat combining nuclear cooling with dilution refrigeration operational
1978 
Double nuclear cooling in operation
1979 
100 kW superconducting motor built and successfully tested
1980 
Millikelvin temperatures in a rotating cryostat
1983 
MRI system with a superconducting magnet built for clinical evaluation
1988 
1.6 T magnet built for phosphorus NMR imaging
1993 
World's largest dilution refrigerator for cooling polarized targets completed at CERN
2006 
First dry dilution refrigerator assembled in the laboratory
2007 
BlueFors Cryogenics (LTL spin-off company) was established
2011 
Robust plastic dilution refrigerator was developed
2012 
Five dry dilution refrigerators are running in the laboratory and dry demagnetization refrigerator is under development (in cooperation with BlueFors Cryogenics)
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